API Reference

Top-Level Objects

class altair.Chart(data=Undefined, encoding=Undefined, mark=Undefined, width=Undefined, height=Undefined, **kwargs)

Create a basic Altair/Vega-Lite chart.

Although it is possible to set all Chart properties as constructor attributes, it is more idiomatic to use methods such as mark_point(), encode(), transform_filter(), properties(), etc. See Altair’s documentation for details and examples: http://altair-viz.github.io/.

Attributes

data (Data) An object describing the data source
mark (AnyMark) A string describing the mark type (one of “bar”, “circle”, “square”, “tick”, “line”, * “area”, “point”, “rule”, “geoshape”, and “text”) or a MarkDef object.
encoding (EncodingWithFacet) A key-value mapping between encoding channels and definition of fields.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
description (string) Description of this mark for commenting purpose.
height (float) The height of a visualization.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
projection (Projection) An object defining properties of geographic projection. Works with “geoshape” marks and “point” or “line” marks that have a channel (one or more of “X”, “X2”, “Y”, “Y2”) with type “latitude”, or “longitude”.
selection (Mapping(required=[])) A key-value mapping between selection names and definitions.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
width (float) The width of a visualization.
facet(row=Undefined, column=Undefined, data=Undefined, **kwargs)

Create a facet chart from the current chart.

Faceted charts require data to be specified at the top level; if data is not specified, the data from the current chart will be used at the top level.

interactive(name=None, bind_x=True, bind_y=True)

Make chart axes scales interactive

Parameters:

name : string

The selection name to use for the axes scales. This name should be unique among all selections within the chart.

bind_x : boolean, default True

If true, then bind the interactive scales to the x-axis

bind_y : boolean, default True

If true, then bind the interactive scales to the y-axis

Returns:

chart :

copy of self, with interactive axes added

class altair.LayerChart(data=Undefined, layer=(), **kwargs)

A Chart with layers within a single panel Mapping(required=[layer])

Attributes

layer (List(anyOf(LayerSpec, CompositeUnitSpec))) Layer or single view specifications to be layered. __Note__: Specifications inside layer cannot use row and column channels as layering facet specifications is not allowed.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
encoding (Encoding) A shared key-value mapping between encoding channels and definition of fields in the underlying layers.
height (float) The height of a visualization. __Default value:__ - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its y-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - For y-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the height is [determined by the range step, paddings, and the cardinality of the field mapped to y-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to y channel, the height will be the value of rangeStep. __Note__: For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the height of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
projection (Projection) An object defining properties of the geographic projection shared by underlying layers.
resolve (Resolve) Scale, axis, and legend resolutions for layers.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
width (float) The width of a visualization. __Default value:__ This will be determined by the following rules: - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its x-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - For x-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the width is [determined by the range step, paddings, and the cardinality of the field mapped to x-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to x channel, the width will be the value of [config.scale.textXRangeStep](https://vega.github.io/vega-lite/docs/size.html#default-width-and-height) for text mark and the value of rangeStep for other marks. __Note:__ For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the width of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
facet(row=Undefined, column=Undefined, data=Undefined, **kwargs)

Create a facet chart from the current chart.

Faceted charts require data to be specified at the top level; if data is not specified, the data from the current chart will be used at the top level.

interactive(name=None, bind_x=True, bind_y=True)

Make chart axes scales interactive

Parameters:

name : string

The selection name to use for the axes scales. This name should be unique among all selections within the chart.

bind_x : boolean, default True

If true, then bind the interactive scales to the x-axis

bind_y : boolean, default True

If true, then bind the interactive scales to the y-axis

Returns:

chart :

copy of self, with interactive axes added

class altair.HConcatChart(hconcat=(), **kwargs)

A chart with horizontally-concatenated facets Mapping(required=[hconcat])

Attributes

hconcat (List(Spec)) A list of views that should be concatenated and put into a row.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale, axis, and legend resolutions for horizontally concatenated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.VConcatChart(vconcat=(), **kwargs)

A chart with vertically-concatenated facets Mapping(required=[vconcat])

Attributes

vconcat (List(Spec)) A list of views that should be concatenated and put into a column.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale, axis, and legend resolutions for vertically concatenated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.FacetChart(spec, facet=Undefined, **kwargs)

A Chart with layers within a single panel Mapping(required=[data, facet, spec])

Attributes

data (Data) An object describing the data source
facet (FacetMapping) An object that describes mappings between row and column channels and their field definitions.
spec (anyOf(LayerSpec, CompositeUnitSpec)) A specification of the view that gets faceted.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale, axis, and legend resolutions for facets.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
interactive(name=None, bind_x=True, bind_y=True)

Make chart axes scales interactive

Parameters:

name : string

The selection name to use for the axes scales. This name should be unique among all selections within the chart.

bind_x : boolean, default True

If true, then bind the interactive scales to the x-axis

bind_y : boolean, default True

If true, then bind the interactive scales to the y-axis

Returns:

chart :

copy of self, with interactive axes added

class altair.RepeatChart(spec=Undefined, data=Undefined, repeat=Undefined, **kwargs)

A chart repeated across rows and columns with small changes Mapping(required=[repeat, spec])

Attributes

repeat
spec (Spec)
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale and legend resolutions for repeated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
interactive(name=None, bind_x=True, bind_y=True)

Make chart axes scales interactive

Parameters:

name : string

The selection name to use for the axes scales. This name should be unique among all selections within the chart.

bind_x : boolean, default True

If true, then bind the interactive scales to the x-axis

bind_y : boolean, default True

If true, then bind the interactive scales to the y-axis

Returns:

chart :

copy of self, with interactive axes added

Encoding Channels

class altair.Color(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Color schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.ColorValue(value, condition=Undefined, **kwds)

ColorValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Column(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, header=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Column schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
header (Header) An object defining properties of a facet’s header.
sort (SortOrder) Sort order for a facet field. This can be “ascending”, “descending”.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Detail(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Detail schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Href(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Href schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.HrefValue(value, condition=Undefined, **kwds)

HrefValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalFieldDef, ConditionalValueDef, List(ConditionalValueDef))) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Opacity(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Opacity schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.OpacityValue(value, condition=Undefined, **kwds)

OpacityValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Order(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Order schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
sort (SortOrder) The sort order. One of “ascending” (default) or “descending”.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Row(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, header=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Row schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
header (Header) An object defining properties of a facet’s header.
sort (SortOrder) Sort order for a facet field. This can be “ascending”, “descending”.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Shape(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Shape schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.ShapeValue(value, condition=Undefined, **kwds)

ShapeValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Size(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Size schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.SizeValue(value, condition=Undefined, **kwds)

SizeValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Text(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, format=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Text schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
format (string) The [formatting pattern](https://vega.github.io/vega-lite/docs/format.html) for a text field. If not defined, this will be determined automatically.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.TextValue(value, condition=Undefined, **kwds)

TextValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalTextFieldDef, ConditionalValueDef, List(ConditionalValueDef))) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Tooltip(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, format=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Tooltip schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
format (string) The [formatting pattern](https://vega.github.io/vega-lite/docs/format.html) for a text field. If not defined, this will be determined automatically.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.TooltipValue(value, condition=Undefined, **kwds)

TooltipValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalTextFieldDef, ConditionalValueDef, List(ConditionalValueDef))) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.X(shorthand=Undefined, aggregate=Undefined, axis=Undefined, bin=Undefined, field=Undefined, scale=Undefined, sort=Undefined, stack=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

X schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
axis (anyOf(Axis, None)) An object defining properties of axis’s gridlines, ticks and labels. If null, the axis for the encoding channel will be removed. __Default value:__ If undefined, default [axis properties](https://vega.github.io/vega-lite/docs/axis.html) are applied.
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
stack (anyOf(StackOffset, None)) Type of stacking offset if the field should be stacked. stack is only applicable for x and y channels with continuous domains. For example, stack of y can be used to customize stacking for a vertical bar chart. stack can be one of the following values: - “zero”: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart). - “normalize” - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/> -“center” - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)). - null - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart. __Default value:__ zero for plots with all of the following conditions are true: (1) the mark is bar or area; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, null by default.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.XValue(value, **kwds)

XValue schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.X2(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

X2 schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.X2Value(value, **kwds)

X2Value schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.Y(shorthand=Undefined, aggregate=Undefined, axis=Undefined, bin=Undefined, field=Undefined, scale=Undefined, sort=Undefined, stack=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Y schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
axis (anyOf(Axis, None)) An object defining properties of axis’s gridlines, ticks and labels. If null, the axis for the encoding channel will be removed. __Default value:__ If undefined, default [axis properties](https://vega.github.io/vega-lite/docs/axis.html) are applied.
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
stack (anyOf(StackOffset, None)) Type of stacking offset if the field should be stacked. stack is only applicable for x and y channels with continuous domains. For example, stack of y can be used to customize stacking for a vertical bar chart. stack can be one of the following values: - “zero”: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart). - “normalize” - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/> -“center” - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)). - null - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart. __Default value:__ zero for plots with all of the following conditions are true: (1) the mark is bar or area; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, null by default.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.YValue(value, **kwds)

YValue schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.Y2(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Y2 schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Y2Value(value, **kwds)

Y2Value schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).

Other Objects

class altair.Aggregate(*args)

Aggregate schema wrapper

enum(‘argmax’, ‘argmin’, ‘average’, ‘count’, ‘distinct’, ‘max’, ‘mean’, ‘median’, ‘min’, ‘missing’, ‘q1’, ‘q3’, ‘ci0’, ‘ci1’, ‘stderr’, ‘stdev’, ‘stdevp’, ‘sum’, ‘valid’, ‘values’, ‘variance’, ‘variancep’)

class altair.AggregateOp(*args)

AggregateOp schema wrapper

enum(‘argmax’, ‘argmin’, ‘average’, ‘count’, ‘distinct’, ‘max’, ‘mean’, ‘median’, ‘min’, ‘missing’, ‘q1’, ‘q3’, ‘ci0’, ‘ci1’, ‘stderr’, ‘stdev’, ‘stdevp’, ‘sum’, ‘valid’, ‘values’, ‘variance’, ‘variancep’)

class altair.AggregateTransform(aggregate=Undefined, groupby=Undefined, **kwds)

AggregateTransform schema wrapper

Mapping(required=[aggregate])

Attributes

aggregate (List(AggregatedFieldDef)) Array of objects that define fields to aggregate.
groupby (List(string)) The data fields to group by. If not specified, a single group containing all data objects will be used.
class altair.AggregatedFieldDef(field=Undefined, op=Undefined, **kwds)

AggregatedFieldDef schema wrapper

Mapping(required=[op, field, as])

Attributes

field (string) The data field for which to compute aggregate function.
op (AggregateOp) The aggregation operations to apply to the fields, such as sum, average or count. See the [full list of supported aggregation operations](https://vega.github.io/vega-lite/docs/aggregate.html#ops) for more information.
class altair.Anchor(*args)

Anchor schema wrapper

enum(‘start’, ‘middle’, ‘end’)

class altair.AnyMark(*args, **kwds)

AnyMark schema wrapper

anyOf(Mark, MarkDef)

class altair.AutoSizeParams(contains=Undefined, resize=Undefined, type=Undefined, **kwds)

AutoSizeParams schema wrapper

Mapping(required=[])

Attributes

contains (enum(‘content’, ‘padding’)) Determines how size calculation should be performed, one of “content” or “padding”. The default setting (“content”) interprets the width and height settings as the data rectangle (plotting) dimensions, to which padding is then added. In contrast, the “padding” setting includes the padding within the view size calculations, such that the width and height settings indicate the total intended size of the view. __Default value__: “content”
resize (boolean) A boolean flag indicating if autosize layout should be re-calculated on every view update. __Default value__: false
type (AutosizeType) The sizing format type. One of “pad”, “fit” or “none”. See the [autosize type](https://vega.github.io/vega-lite/docs/size.html#autosize) documentation for descriptions of each. __Default value__: “pad”
class altair.AutosizeType(*args)

AutosizeType schema wrapper

enum(‘pad’, ‘fit’, ‘none’)

class altair.Axis(domain=Undefined, format=Undefined, grid=Undefined, labelAngle=Undefined, labelBound=Undefined, labelFlush=Undefined, labelOverlap=Undefined, labelPadding=Undefined, labels=Undefined, maxExtent=Undefined, minExtent=Undefined, offset=Undefined, orient=Undefined, position=Undefined, tickCount=Undefined, tickSize=Undefined, ticks=Undefined, title=Undefined, titleMaxLength=Undefined, titlePadding=Undefined, values=Undefined, zindex=Undefined, **kwds)

Axis schema wrapper

Mapping(required=[])

Attributes

domain (boolean) A boolean flag indicating if the domain (the axis baseline) should be included as part of the axis. __Default value:__ true
format (string) The formatting pattern for labels. This is D3’s [number format pattern](https://github.com/d3/d3-format#locale_format) for quantitative fields and D3’s [time format pattern](https://github.com/d3/d3-time-format#locale_format) for time field. See the [format documentation](format.html) for more information. __Default value:__ derived from [numberFormat](config.html#format) config for quantitative fields and from [timeFormat](config.html#format) config for temporal fields.
grid (boolean) A boolean flag indicating if grid lines should be included as part of the axis __Default value:__ true for [continuous scales](scale.html#continuous) that are not binned; otherwise, false.
labelAngle (float) The rotation angle of the axis labels. __Default value:__ -90 for nominal and ordinal fields; 0 otherwise.
labelBound (anyOf(boolean, float)) Indicates if labels should be hidden if they exceed the axis range. If false `(the default) no bounds overlap analysis is performed. If `true, labels will be hidden if they exceed the axis range by more than 1 pixel. If this property is a number, it specifies the pixel tolerance: the maximum amount by which a label bounding box may exceed the axis range. __Default value:__ false.
labelFlush (anyOf(boolean, float)) Indicates if the first and last axis labels should be aligned flush with the scale range. Flush alignment for a horizontal axis will left-align the first label and right-align the last label. For vertical axes, bottom and top text baselines are applied instead. If this property is a number, it also indicates the number of pixels by which to offset the first and last labels; for example, a value of 2 will flush-align the first and last labels and also push them 2 pixels outward from the center of the axis. The additional adjustment can sometimes help the labels better visually group with corresponding axis ticks. __Default value:__ true for axis of a continuous x-scale. Otherwise, false.
labelOverlap (anyOf(boolean, enum(‘parity’), enum(‘greedy’))) The strategy to use for resolving overlap of axis labels. If false (the default), no overlap reduction is attempted. If set to true or “parity”, a strategy of removing every other label is used (this works well for standard linear axes). If set to “greedy”, a linear scan of the labels is performed, removing any labels that overlaps with the last visible label (this often works better for log-scaled axes). __Default value:__ true for non-nominal fields with non-log scales; “greedy” for log scales; otherwise false.
labelPadding (float) The padding, in pixels, between axis and text labels.
labels (boolean) A boolean flag indicating if labels should be included as part of the axis. __Default value:__ true.
maxExtent (float) The maximum extent in pixels that axis ticks and labels should use. This determines a maximum offset value for axis titles. __Default value:__ undefined.
minExtent (float) The minimum extent in pixels that axis ticks and labels should use. This determines a minimum offset value for axis titles. __Default value:__ 30 for y-axis; undefined for x-axis.
offset (float) The offset, in pixels, by which to displace the axis from the edge of the enclosing group or data rectangle. __Default value:__ derived from the [axis config](config.html#facet-scale-config)’s offset (0 by default)
orient (AxisOrient) The orientation of the axis. One of “top”, “bottom”, “left” or “right”. The orientation can be used to further specialize the axis type (e.g., a y axis oriented for the right edge of the chart). __Default value:__ “bottom” for x-axes and “left” for y-axes.
position (float) The anchor position of the axis in pixels. For x-axis with top or bottom orientation, this sets the axis group x coordinate. For y-axis with left or right orientation, this sets the axis group y coordinate. __Default value__: 0
tickCount (float) A desired number of ticks, for axes visualizing quantitative scales. The resulting number may be different so that values are “nice” (multiples of 2, 5, 10) and lie within the underlying scale’s range.
tickSize (float) The size in pixels of axis ticks.
ticks (boolean) Boolean value that determines whether the axis should include ticks.
title (anyOf(string, None)) A title for the field. If null, the title will be removed. __Default value:__ derived from the field’s name and transformation function (aggregate, bin and timeUnit). If the field has an aggregate function, the function is displayed as a part of the title (e.g., “Sum of Profit”). If the field is binned or has a time unit applied, the applied function will be denoted in parentheses (e.g., “Profit (binned)”, “Transaction Date (year-month)”). Otherwise, the title is simply the field name. __Note__: You can customize the default field title format by providing the [fieldTitle property in the [config](config.html) or [fieldTitle function via the compile function’s options](compile.html#field-title).
titleMaxLength (float) Max length for axis title if the title is automatically generated from the field’s description.
titlePadding (float) The padding, in pixels, between title and axis.
values (anyOf(List(float), List(DateTime))) Explicitly set the visible axis tick values.
zindex (float) A non-positive integer indicating z-index of the axis. If zindex is 0, axes should be drawn behind all chart elements. To put them in front, use “zindex = 1”. __Default value:__ 1 (in front of the marks) for actual axis and 0 (behind the marks) for grids.
class altair.AxisConfig(bandPosition=Undefined, domain=Undefined, domainColor=Undefined, domainWidth=Undefined, grid=Undefined, gridColor=Undefined, gridDash=Undefined, gridOpacity=Undefined, gridWidth=Undefined, labelAngle=Undefined, labelBound=Undefined, labelColor=Undefined, labelFlush=Undefined, labelFont=Undefined, labelFontSize=Undefined, labelLimit=Undefined, labelOverlap=Undefined, labelPadding=Undefined, labels=Undefined, maxExtent=Undefined, minExtent=Undefined, shortTimeLabels=Undefined, tickColor=Undefined, tickRound=Undefined, tickSize=Undefined, tickWidth=Undefined, ticks=Undefined, titleAlign=Undefined, titleAngle=Undefined, titleBaseline=Undefined, titleColor=Undefined, titleFont=Undefined, titleFontSize=Undefined, titleFontWeight=Undefined, titleLimit=Undefined, titleMaxLength=Undefined, titlePadding=Undefined, titleX=Undefined, titleY=Undefined, **kwds)

AxisConfig schema wrapper

Mapping(required=[])

Attributes

bandPosition (float) An interpolation fraction indicating where, for band scales, axis ticks should be positioned. A value of 0 places ticks at the left edge of their bands. A value of 0.5 places ticks in the middle of their bands.
domain (boolean) A boolean flag indicating if the domain (the axis baseline) should be included as part of the axis. __Default value:__ true
domainColor (string) Color of axis domain line. __Default value:__ (none, using Vega default).
domainWidth (float) Stroke width of axis domain line __Default value:__ (none, using Vega default).
grid (boolean) A boolean flag indicating if grid lines should be included as part of the axis __Default value:__ true for [continuous scales](scale.html#continuous) that are not binned; otherwise, false.
gridColor (string) Color of gridlines.
gridDash (List(float)) The offset (in pixels) into which to begin drawing with the grid dash array.
gridOpacity (float) The stroke opacity of grid (value between [0,1]) __Default value:__ (1 by default)
gridWidth (float) The grid width, in pixels.
labelAngle (float) The rotation angle of the axis labels. __Default value:__ -90 for nominal and ordinal fields; 0 otherwise.
labelBound (anyOf(boolean, float)) Indicates if labels should be hidden if they exceed the axis range. If false `(the default) no bounds overlap analysis is performed. If `true, labels will be hidden if they exceed the axis range by more than 1 pixel. If this property is a number, it specifies the pixel tolerance: the maximum amount by which a label bounding box may exceed the axis range. __Default value:__ false.
labelColor (string) The color of the tick label, can be in hex color code or regular color name.
labelFlush (anyOf(boolean, float)) Indicates if the first and last axis labels should be aligned flush with the scale range. Flush alignment for a horizontal axis will left-align the first label and right-align the last label. For vertical axes, bottom and top text baselines are applied instead. If this property is a number, it also indicates the number of pixels by which to offset the first and last labels; for example, a value of 2 will flush-align the first and last labels and also push them 2 pixels outward from the center of the axis. The additional adjustment can sometimes help the labels better visually group with corresponding axis ticks. __Default value:__ true for axis of a continuous x-scale. Otherwise, false.
labelFont (string) The font of the tick label.
labelFontSize (float) The font size of the label, in pixels.
labelLimit (float) Maximum allowed pixel width of axis tick labels.
labelOverlap (anyOf(boolean, enum(‘parity’), enum(‘greedy’))) The strategy to use for resolving overlap of axis labels. If false (the default), no overlap reduction is attempted. If set to true or “parity”, a strategy of removing every other label is used (this works well for standard linear axes). If set to “greedy”, a linear scan of the labels is performed, removing any labels that overlaps with the last visible label (this often works better for log-scaled axes). __Default value:__ true for non-nominal fields with non-log scales; “greedy” for log scales; otherwise false.
labelPadding (float) The padding, in pixels, between axis and text labels.
labels (boolean) A boolean flag indicating if labels should be included as part of the axis. __Default value:__ true.
maxExtent (float) The maximum extent in pixels that axis ticks and labels should use. This determines a maximum offset value for axis titles. __Default value:__ undefined.
minExtent (float) The minimum extent in pixels that axis ticks and labels should use. This determines a minimum offset value for axis titles. __Default value:__ 30 for y-axis; undefined for x-axis.
shortTimeLabels (boolean) Whether month names and weekday names should be abbreviated. __Default value:__ false
tickColor (string) The color of the axis’s tick.
tickRound (boolean) Boolean flag indicating if pixel position values should be rounded to the nearest integer.
tickSize (float) The size in pixels of axis ticks.
tickWidth (float) The width, in pixels, of ticks.
ticks (boolean) Boolean value that determines whether the axis should include ticks.
titleAlign (string) Horizontal text alignment of axis titles.
titleAngle (float) Angle in degrees of axis titles.
titleBaseline (string) Vertical text baseline for axis titles.
titleColor (string) Color of the title, can be in hex color code or regular color name.
titleFont (string) Font of the title. (e.g., “Helvetica Neue”).
titleFontSize (float) Font size of the title.
titleFontWeight (FontWeight) Font weight of the title. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
titleLimit (float) Maximum allowed pixel width of axis titles.
titleMaxLength (float) Max length for axis title if the title is automatically generated from the field’s description.
titlePadding (float) The padding, in pixels, between title and axis.
titleX (float) X-coordinate of the axis title relative to the axis group.
titleY (float) Y-coordinate of the axis title relative to the axis group.
class altair.AxisOrient(*args)

AxisOrient schema wrapper

enum(‘top’, ‘right’, ‘left’, ‘bottom’)

class altair.AxisResolveMap(x=Undefined, y=Undefined, **kwds)

AxisResolveMap schema wrapper

Mapping(required=[])

Attributes

x (ResolveMode)
y (ResolveMode)
class altair.BarConfig(align=Undefined, angle=Undefined, baseline=Undefined, binSpacing=Undefined, color=Undefined, continuousBandSize=Undefined, cursor=Undefined, discreteBandSize=Undefined, dx=Undefined, dy=Undefined, fill=Undefined, fillOpacity=Undefined, filled=Undefined, font=Undefined, fontSize=Undefined, fontStyle=Undefined, fontWeight=Undefined, href=Undefined, interpolate=Undefined, limit=Undefined, opacity=Undefined, orient=Undefined, radius=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, strokeDash=Undefined, strokeDashOffset=Undefined, strokeOpacity=Undefined, strokeWidth=Undefined, tension=Undefined, text=Undefined, theta=Undefined, **kwds)

BarConfig schema wrapper

Mapping(required=[])

Attributes

align (HorizontalAlign) The horizontal alignment of the text. One of “left”, “right”, “center”.
angle (float) The rotation angle of the text, in degrees.
baseline (VerticalAlign) The vertical alignment of the text. One of “top”, “middle”, “bottom”. __Default value:__ “middle”
binSpacing (float) Offset between bar for binned field. Ideal value for this is either 0 (Preferred by statisticians) or 1 (Vega-Lite Default, D3 example style). __Default value:__ 1
color (string) Default color. Note that fill and stroke have higher precedence than color and will override color. __Default value:__ <span style=”color: #4682b4;”>&#9632;</span> “#4682b4” __Note:__ This property cannot be used in a [style config](mark.html#style-config).
continuousBandSize (float) The default size of the bars on continuous scales. __Default value:__ 5
cursor (enum(‘auto’, ‘default’, ‘none’, ‘context-menu’, ‘help’, ‘pointer’, ‘progress’,)
‘wait’, ‘cell’, ‘crosshair’, ‘text’, ‘vertical-text’, ‘alias’, ‘copy’, ‘move’, ‘no-drop’,  
‘not-allowed’, ‘e-resize’, ‘n-resize’, ‘ne-resize’, ‘nw-resize’, ‘s-resize’, ‘se-resize’,  
‘sw-resize’, ‘w-resize’, ‘ew-resize’, ‘ns-resize’, ‘nesw-resize’, ‘nwse-resize’,  
‘col-resize’, ‘row-resize’, ‘all-scroll’, ‘zoom-in’, ‘zoom-out’, ‘grab’, ‘grabbing’) The mouse cursor used over the mark. Any valid [CSS cursor type](https://developer.mozilla.org/en-US/docs/Web/CSS/cursor#Values) can be used.
discreteBandSize (float) The size of the bars. If unspecified, the default size is bandSize-1, which provides 1 pixel offset between bars.
dx (float) The horizontal offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
dy (float) The vertical offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
fill (string) Default Fill Color. This has higher precedence than config.color __Default value:__ (None)
fillOpacity (float) The fill opacity (value between [0,1]). __Default value:__ 1
filled (boolean) Whether the mark’s color should be used as fill color instead of stroke color. __Default value:__ true for all marks except point and false for point. __Applicable for:__ bar, point, circle, square, and area marks. __Note:__ This property cannot be used in a [style config](mark.html#style-config).
font (string) The typeface to set the text in (e.g., “Helvetica Neue”).
fontSize (float) The font size, in pixels.
fontStyle (FontStyle) The font style (e.g., “italic”).
fontWeight (FontWeight) The font weight. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
href (string) A URL to load upon mouse click. If defined, the mark acts as a hyperlink.
interpolate (Interpolate) The line interpolation method to use for line and area marks. One of the following: - “linear”: piecewise linear segments, as in a polyline. - “linear-closed”: close the linear segments to form a polygon. - “step”: alternate between horizontal and vertical segments, as in a step function. - “step-before”: alternate between vertical and horizontal segments, as in a step function. - “step-after”: alternate between horizontal and vertical segments, as in a step function. - “basis”: a B-spline, with control point duplication on the ends. - “basis-open”: an open B-spline; may not intersect the start or end. - “basis-closed”: a closed B-spline, as in a loop. - “cardinal”: a Cardinal spline, with control point duplication on the ends. - “cardinal-open”: an open Cardinal spline; may not intersect the start or end, but will intersect other control points. - “cardinal-closed”: a closed Cardinal spline, as in a loop. - “bundle”: equivalent to basis, except the tension parameter is used to straighten the spline. - “monotone”: cubic interpolation that preserves monotonicity in y.
limit (float) The maximum length of the text mark in pixels (default 0, indicating no limit). The text value will be automatically truncated if the rendered size exceeds the limit.
opacity (float) The overall opacity (value between [0,1]). __Default value:__ 0.7 for non-aggregate plots with point, tick, circle, or square marks or layered bar charts and 1 otherwise.
orient (Orient) The orientation of a non-stacked bar, tick, area, and line charts. The value is either horizontal (default) or vertical. - For bar, rule and tick, this determines whether the size of the bar and tick should be applied to x or y dimension. - For area, this property determines the orient property of the Vega output. - For line, this property determines the sort order of the points in the line if config.sortLineBy is not specified. For stacked charts, this is always determined by the orientation of the stack; therefore explicitly specified value will be ignored.
radius (float) Polar coordinate radial offset, in pixels, of the text label from the origin determined by the x and y properties.
shape (string) The default symbol shape to use. One of: “circle” (default), “square”, “cross”, “diamond”, “triangle-up”, or “triangle-down”, or a custom SVG path. __Default value:__ “circle”
size (float) The pixel area each the point/circle/square. For example: in the case of circles, the radius is determined in part by the square root of the size value. __Default value:__ 30
stroke (string) Default Stroke Color. This has higher precedence than config.color __Default value:__ (None)
strokeDash (List(float)) An array of alternating stroke, space lengths for creating dashed or dotted lines.
strokeDashOffset (float) The offset (in pixels) into which to begin drawing with the stroke dash array.
strokeOpacity (float) The stroke opacity (value between [0,1]). __Default value:__ 1
strokeWidth (float) The stroke width, in pixels.
tension (float) Depending on the interpolation type, sets the tension parameter (for line and area marks).
text (string) Placeholder text if the text channel is not specified
theta (float) Polar coordinate angle, in radians, of the text label from the origin determined by the x and y properties. Values for theta follow the same convention of arc mark startAngle and endAngle properties: angles are measured in radians, with 0 indicating “north”.
class altair.BasicType(*args)

BasicType schema wrapper

enum(‘quantitative’, ‘ordinal’, ‘temporal’, ‘nominal’)

altair.Bin

alias of BinParams

class altair.BinParams(base=Undefined, divide=Undefined, extent=Undefined, maxbins=Undefined, minstep=Undefined, nice=Undefined, step=Undefined, steps=Undefined, **kwds)

BinParams schema wrapper

Mapping(required=[]) Binning properties or boolean flag for determining whether to bin data or not.

Attributes

base (float) The number base to use for automatic bin determination (default is base 10). __Default value:__ 10
divide (List(float)) Scale factors indicating allowable subdivisions. The default value is [5, 2], which indicates that for base 10 numbers (the default base), the method may consider dividing bin sizes by 5 and/or 2. For example, for an initial step size of 10, the method can check if bin sizes of 2 (= 10/5), 5 (= 10/2), or 1 (= 10/(5*2)) might also satisfy the given constraints. __Default value:__ [5, 2]
extent (List(float)) A two-element ([min, max]) array indicating the range of desired bin values.
maxbins (float) Maximum number of bins. __Default value:__ 6 for row, column and shape channels; 10 for other channels
minstep (float) A minimum allowable step size (particularly useful for integer values).
nice (boolean) If true (the default), attempts to make the bin boundaries use human-friendly boundaries, such as multiples of ten.
step (float) An exact step size to use between bins. __Note:__ If provided, options such as maxbins will be ignored.
steps (List(float)) An array of allowable step sizes to choose from.
class altair.BinTransform(bin=Undefined, field=Undefined, **kwds)

BinTransform schema wrapper

Mapping(required=[bin, field, as])

Attributes

bin (anyOf(boolean, BinParams)) An object indicating bin properties, or simply true for using default bin parameters.
field (string) The data field to bin.
class altair.BrushConfig(fill=Undefined, fillOpacity=Undefined, stroke=Undefined, strokeDash=Undefined, strokeDashOffset=Undefined, strokeOpacity=Undefined, strokeWidth=Undefined, **kwds)

BrushConfig schema wrapper

Mapping(required=[])

Attributes

fill (string) The fill color of the interval mark. __Default value:__ #333333
fillOpacity (float) The fill opacity of the interval mark (a value between 0 and 1). __Default value:__ 0.125
stroke (string) The stroke color of the interval mark. __Default value:__ #ffffff
strokeDash (List(float)) An array of alternating stroke and space lengths, for creating dashed or dotted lines.
strokeDashOffset (float) The offset (in pixels) with which to begin drawing the stroke dash array.
strokeOpacity (float) The stroke opacity of the interval mark (a value between 0 and 1).
strokeWidth (float) The stroke width of the interval mark.
class altair.CalculateTransform(calculate=Undefined, **kwds)

CalculateTransform schema wrapper

Mapping(required=[calculate, as])

Attributes

calculate (string) A [expression](https://vega.github.io/vega-lite/docs/types.html#expression) string. Use the variable datum to refer to the current data object.
class altair.Color(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Color schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.ColorValue(value, condition=Undefined, **kwds)

ColorValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Column(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, header=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Column schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
header (Header) An object defining properties of a facet’s header.
sort (SortOrder) Sort order for a facet field. This can be “ascending”, “descending”.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.CompositeUnitSpec(mark=Undefined, data=Undefined, description=Undefined, encoding=Undefined, height=Undefined, name=Undefined, projection=Undefined, selection=Undefined, title=Undefined, transform=Undefined, width=Undefined, **kwds)

CompositeUnitSpec schema wrapper

Mapping(required=[mark])

Attributes

mark (AnyMark) A string describing the mark type (one of “bar”, “circle”, “square”, “tick”, “line”, * “area”, “point”, “rule”, “geoshape”, and “text”) or a [mark definition object](https://vega.github.io/vega-lite/docs/mark.html#mark-def).
data (Data) An object describing the data source
description (string) Description of this mark for commenting purpose.
encoding (Encoding) A key-value mapping between encoding channels and definition of fields.
height (float) The height of a visualization. __Default value:__ - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its y-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - For y-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the height is [determined by the range step, paddings, and the cardinality of the field mapped to y-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to y channel, the height will be the value of rangeStep. __Note__: For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the height of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
name (string) Name of the visualization for later reference.
projection (Projection) An object defining properties of geographic projection. Works with “geoshape” marks and “point” or “line” marks that have latitude and “longitude” channels.
selection (Mapping(required=[])) A key-value mapping between selection names and definitions.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
width (float) The width of a visualization. __Default value:__ This will be determined by the following rules: - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its x-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - For x-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the width is [determined by the range step, paddings, and the cardinality of the field mapped to x-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to x channel, the width will be the value of [config.scale.textXRangeStep](https://vega.github.io/vega-lite/docs/size.html#default-width-and-height) for text mark and the value of rangeStep for other marks. __Note:__ For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the width of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
class altair.CompositeUnitSpecAlias(mark=Undefined, data=Undefined, description=Undefined, encoding=Undefined, height=Undefined, name=Undefined, projection=Undefined, selection=Undefined, title=Undefined, transform=Undefined, width=Undefined, **kwds)

CompositeUnitSpecAlias schema wrapper

Mapping(required=[mark])

Attributes

mark (AnyMark) A string describing the mark type (one of “bar”, “circle”, “square”, “tick”, “line”, * “area”, “point”, “rule”, “geoshape”, and “text”) or a [mark definition object](https://vega.github.io/vega-lite/docs/mark.html#mark-def).
data (Data) An object describing the data source
description (string) Description of this mark for commenting purpose.
encoding (Encoding) A key-value mapping between encoding channels and definition of fields.
height (float) The height of a visualization. __Default value:__ - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its y-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - For y-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the height is [determined by the range step, paddings, and the cardinality of the field mapped to y-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to y channel, the height will be the value of rangeStep. __Note__: For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the height of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
name (string) Name of the visualization for later reference.
projection (Projection) An object defining properties of geographic projection. Works with “geoshape” marks and “point” or “line” marks that have latitude and “longitude” channels.
selection (Mapping(required=[])) A key-value mapping between selection names and definitions.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
width (float) The width of a visualization. __Default value:__ This will be determined by the following rules: - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its x-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - For x-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the width is [determined by the range step, paddings, and the cardinality of the field mapped to x-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to x channel, the width will be the value of [config.scale.textXRangeStep](https://vega.github.io/vega-lite/docs/size.html#default-width-and-height) for text mark and the value of rangeStep for other marks. __Note:__ For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the width of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
class altair.ConditionalFieldDef(*args, **kwds)

ConditionalFieldDef schema wrapper

anyOf(ConditionalPredicateFieldDef, ConditionalSelectionFieldDef)

class altair.ConditionalMarkPropFieldDef(*args, **kwds)

ConditionalMarkPropFieldDef schema wrapper

anyOf(ConditionalPredicateMarkPropFieldDef, ConditionalSelectionMarkPropFieldDef)

class altair.ConditionalPredicateFieldDef(test=Undefined, type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, **kwds)

ConditionalPredicateFieldDef schema wrapper

Mapping(required=[test, type])

Attributes

test (LogicalOperandPredicate)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.ConditionalPredicateMarkPropFieldDef(test=Undefined, type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, **kwds)

ConditionalPredicateMarkPropFieldDef schema wrapper

Mapping(required=[test, type])

Attributes

test (LogicalOperandPredicate)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.ConditionalPredicateTextFieldDef(test=Undefined, type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, format=Undefined, timeUnit=Undefined, **kwds)

ConditionalPredicateTextFieldDef schema wrapper

Mapping(required=[test, type])

Attributes

test (LogicalOperandPredicate)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
format (string) The [formatting pattern](https://vega.github.io/vega-lite/docs/format.html) for a text field. If not defined, this will be determined automatically.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.ConditionalPredicateValueDef(test=Undefined, value=Undefined, **kwds)

ConditionalPredicateValueDef schema wrapper

Mapping(required=[test, value])

Attributes

test (LogicalOperandPredicate)
value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.ConditionalSelectionFieldDef(selection=Undefined, type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, **kwds)

ConditionalSelectionFieldDef schema wrapper

Mapping(required=[selection, type])

Attributes

selection (SelectionOperand) A [selection name](https://vega.github.io/vega-lite/docs/selection.html), or a series of [composed selections](https://vega.github.io/vega-lite/docs/selection.html#compose).
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.ConditionalSelectionMarkPropFieldDef(selection=Undefined, type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, **kwds)

ConditionalSelectionMarkPropFieldDef schema wrapper

Mapping(required=[selection, type])

Attributes

selection (SelectionOperand) A [selection name](https://vega.github.io/vega-lite/docs/selection.html), or a series of [composed selections](https://vega.github.io/vega-lite/docs/selection.html#compose).
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.ConditionalSelectionTextFieldDef(selection=Undefined, type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, format=Undefined, timeUnit=Undefined, **kwds)

ConditionalSelectionTextFieldDef schema wrapper

Mapping(required=[selection, type])

Attributes

selection (SelectionOperand) A [selection name](https://vega.github.io/vega-lite/docs/selection.html), or a series of [composed selections](https://vega.github.io/vega-lite/docs/selection.html#compose).
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
format (string) The [formatting pattern](https://vega.github.io/vega-lite/docs/format.html) for a text field. If not defined, this will be determined automatically.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.ConditionalSelectionValueDef(selection=Undefined, value=Undefined, **kwds)

ConditionalSelectionValueDef schema wrapper

Mapping(required=[selection, value])

Attributes

selection (SelectionOperand) A [selection name](https://vega.github.io/vega-lite/docs/selection.html), or a series of [composed selections](https://vega.github.io/vega-lite/docs/selection.html#compose).
value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.ConditionalTextFieldDef(*args, **kwds)

ConditionalTextFieldDef schema wrapper

anyOf(ConditionalPredicateTextFieldDef, ConditionalSelectionTextFieldDef)

class altair.ConditionalValueDef(*args, **kwds)

ConditionalValueDef schema wrapper

anyOf(ConditionalPredicateValueDef, ConditionalSelectionValueDef)

class altair.Config(area=Undefined, autosize=Undefined, axis=Undefined, axisBand=Undefined, axisBottom=Undefined, axisLeft=Undefined, axisRight=Undefined, axisTop=Undefined, axisX=Undefined, axisY=Undefined, background=Undefined, bar=Undefined, circle=Undefined, countTitle=Undefined, datasets=Undefined, fieldTitle=Undefined, geoshape=Undefined, invalidValues=Undefined, legend=Undefined, line=Undefined, mark=Undefined, numberFormat=Undefined, padding=Undefined, point=Undefined, projection=Undefined, range=Undefined, rect=Undefined, rule=Undefined, scale=Undefined, selection=Undefined, square=Undefined, stack=Undefined, style=Undefined, text=Undefined, tick=Undefined, timeFormat=Undefined, title=Undefined, view=Undefined, **kwds)

Config schema wrapper

Mapping(required=[])

Attributes

area (MarkConfig) Area-Specific Config
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
axis (AxisConfig) Axis configuration, which determines default properties for all x and y [axes](axis.html). For a full list of axis configuration options, please see the [corresponding section of the axis documentation](axis.html#config).
axisBand (VgAxisConfig) Specific axis config for axes with “band” scales.
axisBottom (VgAxisConfig) Specific axis config for x-axis along the bottom edge of the chart.
axisLeft (VgAxisConfig) Specific axis config for y-axis along the left edge of the chart.
axisRight (VgAxisConfig) Specific axis config for y-axis along the right edge of the chart.
axisTop (VgAxisConfig) Specific axis config for x-axis along the top edge of the chart.
axisX (VgAxisConfig) X-axis specific config.
axisY (VgAxisConfig) Y-axis specific config.
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
bar (BarConfig) Bar-Specific Config
circle (MarkConfig) Circle-Specific Config
countTitle (string) Default axis and legend title for count fields. __Default value:__ ‘Number of Records’.
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
fieldTitle (enum(‘verbal’, ‘functional’, ‘plain’)) Defines how Vega-Lite generates title for fields. There are three possible styles: - “verbal” (Default) - displays function in a verbal style (e.g., “Sum of field”, “Year-month of date”, “field (binned)”). - “function” - displays function using parentheses and capitalized texts (e.g., “SUM(field)”, “YEARMONTH(date)”, “BIN(field)”). - “plain” - displays only the field name without functions (e.g., “field”, “date”, “field”).
geoshape (MarkConfig) Geoshape-Specific Config
invalidValues (enum(‘filter’, None)) Defines how Vega-Lite should handle invalid values (null and NaN). - If set to “filter” (default), all data items with null values are filtered. - If null, all data items are included. In this case, invalid values will be interpreted as zeroes.
legend (LegendConfig) Legend configuration, which determines default properties for all [legends](legend.html). For a full list of legend configuration options, please see the [corresponding section of in the legend documentation](legend.html#config).
line (MarkConfig) Line-Specific Config
mark (MarkConfig) Mark Config
numberFormat (string) D3 Number format for axis labels and text tables. For example “s” for SI units. Use [D3’s number format pattern](https://github.com/d3/d3-format#locale_format).
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
point (MarkConfig) Point-Specific Config
projection (ProjectionConfig) Projection configuration, which determines default properties for all [projections](projection.html). For a full list of projection configuration options, please see the [corresponding section of the projection documentation](projection.html#config).
range (RangeConfig) An object hash that defines default range arrays or schemes for using with scales. For a full list of scale range configuration options, please see the [corresponding section of the scale documentation](scale.html#config).
rect (MarkConfig) Rect-Specific Config
rule (MarkConfig) Rule-Specific Config
scale (ScaleConfig) Scale configuration determines default properties for all [scales](scale.html). For a full list of scale configuration options, please see the [corresponding section of the scale documentation](scale.html#config).
selection (SelectionConfig) An object hash for defining default properties for each type of selections.
square (MarkConfig) Square-Specific Config
stack (StackOffset) Default stack offset for stackable mark.
style (StyleConfigIndex) An object hash that defines key-value mappings to determine default properties for marks with a given [style](mark.html#mark-def). The keys represent styles names; the value are valid [mark configuration objects](mark.html#config).
text (TextConfig) Text-Specific Config
tick (TickConfig) Tick-Specific Config
timeFormat (string) Default datetime format for axis and legend labels. The format can be set directly on each axis and legend. Use [D3’s time format pattern](https://github.com/d3/d3-time-format#locale_format). __Default value:__ ‘%b %d, %Y’.
title (VgTitleConfig) Title configuration, which determines default properties for all [titles](title.html). For a full list of title configuration options, please see the [corresponding section of the title documentation](title.html#config).
view (ViewConfig) Default properties for [single view plots](spec.html#single).
class altair.CsvDataFormat(parse=Undefined, type=Undefined, **kwds)

CsvDataFormat schema wrapper

Mapping(required=[])

Attributes

parse (anyOf(enum(‘auto’), Mapping(required=[]))) If set to auto (the default), perform automatic type inference to determine the desired data types. Alternatively, a parsing directive object can be provided for explicit data types. Each property of the object corresponds to a field name, and the value to the desired data type (one of “number”, “boolean” or “date”). For example, “parse”: {“modified_on”: “date”} parses the modified_on field in each input record a Date value. For “date”, we parse data based using Javascript’s [Date.parse()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/parse). For Specific date formats can be provided (e.g., {foo: ‘date:”%m%d%Y”’}), using the [d3-time-format syntax](https://github.com/d3/d3-time-format#locale_format). UTC date format parsing is supported similarly (e.g., {foo: ‘utc:”%m%d%Y”’}). See more about [UTC time](timeunit.html#utc)
type (enum(‘csv’, ‘tsv’)) Type of input data: “json”, “csv”, “tsv”. The default format type is determined by the extension of the file URL. If no extension is detected, “json” will be used by default.
class altair.Data(*args, **kwds)

Data schema wrapper

anyOf(UrlData, InlineData, NamedData)

class altair.DataFormat(*args, **kwds)

DataFormat schema wrapper

anyOf(CsvDataFormat, JsonDataFormat, TopoDataFormat)

class altair.Datasets(**kwds)

Datasets schema wrapper

Mapping(required=[])

class altair.DateTime(date=Undefined, day=Undefined, hours=Undefined, milliseconds=Undefined, minutes=Undefined, month=Undefined, quarter=Undefined, seconds=Undefined, utc=Undefined, year=Undefined, **kwds)

DateTime schema wrapper

Mapping(required=[]) Object for defining datetime in Vega-Lite Filter. If both month and quarter are provided, month has higher precedence. day cannot be combined with other date. We accept string for month and day names.

Attributes

date (float) Integer value representing the date from 1-31.
day (anyOf(Day, string)) Value representing the day of a week. This can be one of: (1) integer value – 1 represents Monday; (2) case-insensitive day name (e.g., “Monday”); (3) case-insensitive, 3-character short day name (e.g., “Mon”). <br/> Warning: A DateTime definition object with day`** should not be combined with `year, quarter, month, or date.
hours (float) Integer value representing the hour of a day from 0-23.
milliseconds (float) Integer value representing the millisecond segment of time.
minutes (float) Integer value representing the minute segment of time from 0-59.
month (anyOf(Month, string)) One of: (1) integer value representing the month from 1-12. 1 represents January; (2) case-insensitive month name (e.g., “January”); (3) case-insensitive, 3-character short month name (e.g., “Jan”).
quarter (float) Integer value representing the quarter of the year (from 1-4).
seconds (float) Integer value representing the second segment (0-59) of a time value
utc (boolean) A boolean flag indicating if date time is in utc time. If false, the date time is in local time
year (float) Integer value representing the year.
class altair.Day(*args)

Day schema wrapper

float

class altair.Detail(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Detail schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.DictInlineDataset(**kwds)

DictInlineDataset schema wrapper

Mapping(required=[])

class altair.Encoding(color=Undefined, detail=Undefined, fill=Undefined, href=Undefined, key=Undefined, latitude=Undefined, latitude2=Undefined, longitude=Undefined, longitude2=Undefined, opacity=Undefined, order=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, text=Undefined, tooltip=Undefined, x=Undefined, x2=Undefined, y=Undefined, y2=Undefined, **kwds)

Encoding schema wrapper

Mapping(required=[])

Attributes

color (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Color of the marks – either fill or stroke color based on the filled property of mark definition. By default, color represents fill color for “area”, “bar”, “tick”, “text”, “circle”, and “square” / stroke color for “line” and “point”. __Default value:__ If undefined, the default color depends on [mark config](config.html#mark)’s color property. _Note:_ 1) For fine-grained control over both fill and stroke colors of the marks, please use the fill and stroke channels. 2) See the scale documentation for more information about customizing [color scheme](scale.html#scheme).
detail (anyOf(FieldDef, List(FieldDef))) Additional levels of detail for grouping data in aggregate views and in line and area marks without mapping data to a specific visual channel.
fill (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Fill color of the marks. __Default value:__ If undefined, the default color depends on [mark config](config.html#mark)’s color property. _Note:_ The fill channel has higher precedence than color and will override color value.
href (anyOf(FieldDefWithCondition, ValueDefWithCondition)) A URL to load upon mouse click.
key (FieldDef) A data field to use as a unique key for data binding. When a visualization’s data is updated, the key value will be used to match data elements to existing mark instances. Use a key channel to enable object constancy for transitions over dynamic data.
latitude (FieldDef) Latitude position of geographically projected marks.
latitude2 (FieldDef) Latitude-2 position for geographically projected ranged “area”, “bar”, “rect”, and “rule”.
longitude (FieldDef) Longitude position of geographically projected marks.
longitude2 (FieldDef) Longitude-2 position for geographically projected ranged “area”, “bar”, “rect”, and “rule”.
opacity (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Opacity of the marks – either can be a value or a range. __Default value:__ If undefined, the default opacity depends on [mark config](config.html#mark)’s opacity property.
order (anyOf(OrderFieldDef, List(OrderFieldDef))) Order of the marks. - For stacked marks, this order channel encodes stack order. - For line marks, this order channel encodes order of data points in the lines. This can be useful for creating [a connected scatterplot](https://vega.github.io/vega-lite/examples/layer_connected_scatterplot.html). - Otherwise, this order channel encodes layer order of the marks. __Note__: In aggregate plots, order field should be `aggregate`d to avoid creating additional aggregation grouping.
shape (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) For point marks the supported values are “circle” (default), “square”, “cross”, “diamond”, “triangle-up”, or “triangle-down”, or else a custom SVG path string. For geoshape marks it should be a field definition of the geojson data __Default value:__ If undefined, the default shape depends on [mark config](config.html#point-config)’s shape property.
size (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Size of the mark. - For “point”, “square” and “circle”, – the symbol size, or pixel area of the mark. - For “bar” and “tick” – the bar and tick’s size. - For “text” – the text’s font size. - Size is currently unsupported for “line”, “area”, and “rect”.
stroke (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Stroke color of the marks. __Default value:__ If undefined, the default color depends on [mark config](config.html#mark)’s color property. _Note:_ The stroke channel has higher precedence than color and will override color value.
text (anyOf(TextFieldDefWithCondition, TextValueDefWithCondition)) Text of the text mark.
tooltip (anyOf(TextFieldDefWithCondition, TextValueDefWithCondition)) The tooltip text to show upon mouse hover.
x (anyOf(PositionFieldDef, ValueDef)) X coordinates of the marks, or width of horizontal “bar” and “area”.
x2 (anyOf(FieldDef, ValueDef)) X2 coordinates for ranged “area”, “bar”, “rect”, and “rule”.
y (anyOf(PositionFieldDef, ValueDef)) Y coordinates of the marks, or height of vertical “bar” and “area”.
y2 (anyOf(FieldDef, ValueDef)) Y2 coordinates for ranged “area”, “bar”, “rect”, and “rule”.
class altair.EncodingWithFacet(color=Undefined, column=Undefined, detail=Undefined, fill=Undefined, href=Undefined, key=Undefined, latitude=Undefined, latitude2=Undefined, longitude=Undefined, longitude2=Undefined, opacity=Undefined, order=Undefined, row=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, text=Undefined, tooltip=Undefined, x=Undefined, x2=Undefined, y=Undefined, y2=Undefined, **kwds)

EncodingWithFacet schema wrapper

Mapping(required=[])

Attributes

color (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Color of the marks – either fill or stroke color based on the filled property of mark definition. By default, color represents fill color for “area”, “bar”, “tick”, “text”, “circle”, and “square” / stroke color for “line” and “point”. __Default value:__ If undefined, the default color depends on [mark config](config.html#mark)’s color property. _Note:_ 1) For fine-grained control over both fill and stroke colors of the marks, please use the fill and stroke channels. 2) See the scale documentation for more information about customizing [color scheme](scale.html#scheme).
column (FacetFieldDef) Horizontal facets for trellis plots.
detail (anyOf(FieldDef, List(FieldDef))) Additional levels of detail for grouping data in aggregate views and in line and area marks without mapping data to a specific visual channel.
fill (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Fill color of the marks. __Default value:__ If undefined, the default color depends on [mark config](config.html#mark)’s color property. _Note:_ The fill channel has higher precedence than color and will override color value.
href (anyOf(FieldDefWithCondition, ValueDefWithCondition)) A URL to load upon mouse click.
key (FieldDef) A data field to use as a unique key for data binding. When a visualization’s data is updated, the key value will be used to match data elements to existing mark instances. Use a key channel to enable object constancy for transitions over dynamic data.
latitude (FieldDef) Latitude position of geographically projected marks.
latitude2 (FieldDef) Latitude-2 position for geographically projected ranged “area”, “bar”, “rect”, and “rule”.
longitude (FieldDef) Longitude position of geographically projected marks.
longitude2 (FieldDef) Longitude-2 position for geographically projected ranged “area”, “bar”, “rect”, and “rule”.
opacity (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Opacity of the marks – either can be a value or a range. __Default value:__ If undefined, the default opacity depends on [mark config](config.html#mark)’s opacity property.
order (anyOf(OrderFieldDef, List(OrderFieldDef))) Order of the marks. - For stacked marks, this order channel encodes stack order. - For line marks, this order channel encodes order of data points in the lines. This can be useful for creating [a connected scatterplot](https://vega.github.io/vega-lite/examples/layer_connected_scatterplot.html). - Otherwise, this order channel encodes layer order of the marks. __Note__: In aggregate plots, order field should be `aggregate`d to avoid creating additional aggregation grouping.
row (FacetFieldDef) Vertical facets for trellis plots.
shape (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) For point marks the supported values are “circle” (default), “square”, “cross”, “diamond”, “triangle-up”, or “triangle-down”, or else a custom SVG path string. For geoshape marks it should be a field definition of the geojson data __Default value:__ If undefined, the default shape depends on [mark config](config.html#point-config)’s shape property.
size (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Size of the mark. - For “point”, “square” and “circle”, – the symbol size, or pixel area of the mark. - For “bar” and “tick” – the bar and tick’s size. - For “text” – the text’s font size. - Size is currently unsupported for “line”, “area”, and “rect”.
stroke (anyOf(MarkPropFieldDefWithCondition, MarkPropValueDefWithCondition)) Stroke color of the marks. __Default value:__ If undefined, the default color depends on [mark config](config.html#mark)’s color property. _Note:_ The stroke channel has higher precedence than color and will override color value.
text (anyOf(TextFieldDefWithCondition, TextValueDefWithCondition)) Text of the text mark.
tooltip (anyOf(TextFieldDefWithCondition, TextValueDefWithCondition)) The tooltip text to show upon mouse hover.
x (anyOf(PositionFieldDef, ValueDef)) X coordinates of the marks, or width of horizontal “bar” and “area”.
x2 (anyOf(FieldDef, ValueDef)) X2 coordinates for ranged “area”, “bar”, “rect”, and “rule”.
y (anyOf(PositionFieldDef, ValueDef)) Y coordinates of the marks, or height of vertical “bar” and “area”.
y2 (anyOf(FieldDef, ValueDef)) Y2 coordinates for ranged “area”, “bar”, “rect”, and “rule”.
class altair.FacetFieldDef(type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, header=Undefined, sort=Undefined, timeUnit=Undefined, **kwds)

FacetFieldDef schema wrapper

Mapping(required=[type])

Attributes

type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
header (Header) An object defining properties of a facet’s header.
sort (SortOrder) Sort order for a facet field. This can be “ascending”, “descending”.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.FacetMapping(column=Undefined, row=Undefined, **kwds)

FacetMapping schema wrapper

Mapping(required=[])

Attributes

column (FacetFieldDef) Horizontal facets for trellis plots.
row (FacetFieldDef) Vertical facets for trellis plots.
class altair.FacetSpec(facet=Undefined, spec=Undefined, data=Undefined, description=Undefined, name=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, **kwds)

FacetSpec schema wrapper

Mapping(required=[facet, spec])

Attributes

facet (FacetMapping) An object that describes mappings between row and column channels and their field definitions.
spec (anyOf(LayerSpec, CompositeUnitSpec)) A specification of the view that gets faceted.
data (Data) An object describing the data source
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
resolve (Resolve) Scale, axis, and legend resolutions for facets.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.FacetedCompositeUnitSpecAlias(mark=Undefined, data=Undefined, description=Undefined, encoding=Undefined, height=Undefined, name=Undefined, projection=Undefined, selection=Undefined, title=Undefined, transform=Undefined, width=Undefined, **kwds)

FacetedCompositeUnitSpecAlias schema wrapper

Mapping(required=[mark])

Attributes

mark (AnyMark) A string describing the mark type (one of “bar”, “circle”, “square”, “tick”, “line”, * “area”, “point”, “rule”, “geoshape”, and “text”) or a [mark definition object](https://vega.github.io/vega-lite/docs/mark.html#mark-def).
data (Data) An object describing the data source
description (string) Description of this mark for commenting purpose.
encoding (EncodingWithFacet) A key-value mapping between encoding channels and definition of fields.
height (float) The height of a visualization. __Default value:__ - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its y-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - For y-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the height is [determined by the range step, paddings, and the cardinality of the field mapped to y-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to y channel, the height will be the value of rangeStep. __Note__: For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the height of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
name (string) Name of the visualization for later reference.
projection (Projection) An object defining properties of geographic projection. Works with “geoshape” marks and “point” or “line” marks that have latitude and “longitude” channels.
selection (Mapping(required=[])) A key-value mapping between selection names and definitions.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
width (float) The width of a visualization. __Default value:__ This will be determined by the following rules: - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its x-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - For x-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the width is [determined by the range step, paddings, and the cardinality of the field mapped to x-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to x channel, the width will be the value of [config.scale.textXRangeStep](https://vega.github.io/vega-lite/docs/size.html#default-width-and-height) for text mark and the value of rangeStep for other marks. __Note:__ For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the width of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
class altair.FieldDef(type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, **kwds)

FieldDef schema wrapper

Mapping(required=[type]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.FieldDefWithCondition(type=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, timeUnit=Undefined, **kwds)

FieldDefWithCondition schema wrapper

Mapping(required=[type]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.FieldEqualPredicate(equal=Undefined, field=Undefined, timeUnit=Undefined, **kwds)

FieldEqualPredicate schema wrapper

Mapping(required=[field, equal])

Attributes

equal (anyOf(string, float, boolean, DateTime)) The value that the field should be equal to.
field (string) Field to be filtered.
timeUnit (TimeUnit) Time unit for the field to be filtered.
class altair.FieldOneOfPredicate(field=Undefined, oneOf=Undefined, timeUnit=Undefined, **kwds)

FieldOneOfPredicate schema wrapper

Mapping(required=[field, oneOf])

Attributes

field (string) Field to be filtered
oneOf (anyOf(List(string), List(float), List(boolean), List(DateTime))) A set of values that the field’s value should be a member of, for a data item included in the filtered data.
timeUnit (TimeUnit) time unit for the field to be filtered.
class altair.FieldRangePredicate(field=Undefined, range=Undefined, timeUnit=Undefined, **kwds)

FieldRangePredicate schema wrapper

Mapping(required=[field, range])

Attributes

field (string) Field to be filtered
range (List(anyOf(float, DateTime, None))) An array of inclusive minimum and maximum values for a field value of a data item to be included in the filtered data.
timeUnit (TimeUnit) time unit for the field to be filtered.
class altair.Fill(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Fill schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.FillValue(value, condition=Undefined, **kwds)

FillValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.FilterTransform(filter=Undefined, **kwds)

FilterTransform schema wrapper

Mapping(required=[filter])

Attributes

filter (LogicalOperandPredicate) The filter property must be one of the predicate definitions: (1) an [expression](https://vega.github.io/vega-lite/docs/types.html#expression) string, where datum can be used to refer to the current data object; (2) one of the field predicates: [equal predicate](https://vega.github.io/vega-lite/docs/filter.html#equal-predicate); [range predicate](filter.html#range-predicate), [one-of predicate](https://vega.github.io/vega-lite/docs/filter.html#one-of-predicate); (3) a [selection predicate](https://vega.github.io/vega-lite/docs/filter.html#selection-predicate); or (4) a logical operand that combines (1), (2), or (3).
class altair.FontStyle(*args)

FontStyle schema wrapper

enum(‘normal’, ‘italic’)

class altair.FontWeight(*args, **kwds)

FontWeight schema wrapper

anyOf(FontWeightString, FontWeightNumber)

class altair.FontWeightNumber(*args)

FontWeightNumber schema wrapper

float

class altair.FontWeightString(*args)

FontWeightString schema wrapper

enum(‘normal’, ‘bold’)

class altair.GeoType(*args)

GeoType schema wrapper

enum(‘latitude’, ‘longitude’, ‘geojson’)

class altair.HConcatChart(hconcat=(), **kwargs)

A chart with horizontally-concatenated facets Mapping(required=[hconcat])

Attributes

hconcat (List(Spec)) A list of views that should be concatenated and put into a row.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale, axis, and legend resolutions for horizontally concatenated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.HConcatSpec(hconcat=Undefined, data=Undefined, description=Undefined, name=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, **kwds)

HConcatSpec schema wrapper

Mapping(required=[hconcat])

Attributes

hconcat (List(Spec)) A list of views that should be concatenated and put into a row.
data (Data) An object describing the data source
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
resolve (Resolve) Scale, axis, and legend resolutions for horizontally concatenated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.Header(format=Undefined, labelAngle=Undefined, title=Undefined, **kwds)

Header schema wrapper

Mapping(required=[]) Headers of row / column channels for faceted plots.

Attributes

format (string) The formatting pattern for labels. This is D3’s [number format pattern](https://github.com/d3/d3-format#locale_format) for quantitative fields and D3’s [time format pattern](https://github.com/d3/d3-time-format#locale_format) for time field. See the [format documentation](format.html) for more information. __Default value:__ derived from [numberFormat](config.html#format) config for quantitative fields and from [timeFormat](config.html#format) config for temporal fields.
labelAngle (float) The rotation angle of the header labels. __Default value:__ 0.
title (anyOf(string, None)) A title for the field. If null, the title will be removed. __Default value:__ derived from the field’s name and transformation function (aggregate, bin and timeUnit). If the field has an aggregate function, the function is displayed as a part of the title (e.g., “Sum of Profit”). If the field is binned or has a time unit applied, the applied function will be denoted in parentheses (e.g., “Profit (binned)”, “Transaction Date (year-month)”). Otherwise, the title is simply the field name. __Note__: You can customize the default field title format by providing the [fieldTitle property in the [config](config.html) or [fieldTitle function via the compile function’s options](compile.html#field-title).
class altair.HorizontalAlign(*args)

HorizontalAlign schema wrapper

enum(‘left’, ‘right’, ‘center’)

class altair.Href(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Href schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.HrefValue(value, condition=Undefined, **kwds)

HrefValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalFieldDef, ConditionalValueDef, List(ConditionalValueDef))) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.InlineData(values=Undefined, format=Undefined, **kwds)

InlineData schema wrapper

Mapping(required=[values])

Attributes

values (InlineDataset) The full data set, included inline. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property. Strings are parsed according to the specified format type.
format (DataFormat) An object that specifies the format for parsing the data values.
class altair.InlineDataset(*args, **kwds)

InlineDataset schema wrapper

anyOf(List(float), List(string), List(boolean), List(Mapping(required=[])), string, Mapping(required=[]))

class altair.Interpolate(*args)

Interpolate schema wrapper

enum(‘linear’, ‘linear-closed’, ‘step’, ‘step-before’, ‘step-after’, ‘basis’, ‘basis-open’, ‘basis-closed’, ‘cardinal’, ‘cardinal-open’, ‘cardinal-closed’, ‘bundle’, ‘monotone’)

class altair.IntervalSelection(type=Undefined, bind=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, mark=Undefined, on=Undefined, resolve=Undefined, translate=Undefined, zoom=Undefined, **kwds)

IntervalSelection schema wrapper

Mapping(required=[type])

Attributes

type (enum(‘interval’))
bind (enum(‘scales’)) Establishes a two-way binding between the interval selection and the scales used within the same view. This allows a user to interactively pan and zoom the view.
empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
mark (BrushConfig) An interval selection also adds a rectangle mark to depict the extents of the interval. The mark property can be used to customize the appearance of the mark.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
translate (anyOf(string, boolean)) When truthy, allows a user to interactively move an interval selection back-and-forth. Can be true, false (to disable panning), or a [Vega event stream definition](https://vega.github.io/vega/docs/event-streams/) which must include a start and end event to trigger continuous panning. __Default value:__ true, which corresponds to [mousedown, window:mouseup] > window:mousemove! which corresponds to clicks and dragging within an interval selection to reposition it.
zoom (anyOf(string, boolean)) When truthy, allows a user to interactively resize an interval selection. Can be true, false (to disable zooming), or a [Vega event stream definition](https://vega.github.io/vega/docs/event-streams/). Currently, only wheel events are supported. __Default value:__ true, which corresponds to wheel!.
class altair.IntervalSelectionConfig(bind=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, mark=Undefined, on=Undefined, resolve=Undefined, translate=Undefined, zoom=Undefined, **kwds)

IntervalSelectionConfig schema wrapper

Mapping(required=[])

Attributes

bind (enum(‘scales’)) Establishes a two-way binding between the interval selection and the scales used within the same view. This allows a user to interactively pan and zoom the view.
empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
mark (BrushConfig) An interval selection also adds a rectangle mark to depict the extents of the interval. The mark property can be used to customize the appearance of the mark.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
translate (anyOf(string, boolean)) When truthy, allows a user to interactively move an interval selection back-and-forth. Can be true, false (to disable panning), or a [Vega event stream definition](https://vega.github.io/vega/docs/event-streams/) which must include a start and end event to trigger continuous panning. __Default value:__ true, which corresponds to [mousedown, window:mouseup] > window:mousemove! which corresponds to clicks and dragging within an interval selection to reposition it.
zoom (anyOf(string, boolean)) When truthy, allows a user to interactively resize an interval selection. Can be true, false (to disable zooming), or a [Vega event stream definition](https://vega.github.io/vega/docs/event-streams/). Currently, only wheel events are supported. __Default value:__ true, which corresponds to wheel!.
class altair.JsonDataFormat(parse=Undefined, property=Undefined, type=Undefined, **kwds)

JsonDataFormat schema wrapper

Mapping(required=[])

Attributes

parse (anyOf(enum(‘auto’), Mapping(required=[]))) If set to auto (the default), perform automatic type inference to determine the desired data types. Alternatively, a parsing directive object can be provided for explicit data types. Each property of the object corresponds to a field name, and the value to the desired data type (one of “number”, “boolean” or “date”). For example, “parse”: {“modified_on”: “date”} parses the modified_on field in each input record a Date value. For “date”, we parse data based using Javascript’s [Date.parse()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/parse). For Specific date formats can be provided (e.g., {foo: ‘date:”%m%d%Y”’}), using the [d3-time-format syntax](https://github.com/d3/d3-time-format#locale_format). UTC date format parsing is supported similarly (e.g., {foo: ‘utc:”%m%d%Y”’}). See more about [UTC time](timeunit.html#utc)
property (string) The JSON property containing the desired data. This parameter can be used when the loaded JSON file may have surrounding structure or meta-data. For example “property”: “values.features” is equivalent to retrieving json.values.features from the loaded JSON object.
type (enum(‘json’)) Type of input data: “json”, “csv”, “tsv”. The default format type is determined by the extension of the file URL. If no extension is detected, “json” will be used by default.
class altair.Key(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Key schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Latitude(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Latitude schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Latitude2(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Latitude2 schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.LayerSpec(layer=Undefined, data=Undefined, description=Undefined, encoding=Undefined, height=Undefined, name=Undefined, projection=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, width=Undefined, **kwds)

LayerSpec schema wrapper

Mapping(required=[layer]) Layer Spec with encoding and projection

Attributes

layer (List(anyOf(LayerSpec, CompositeUnitSpec))) Layer or single view specifications to be layered. __Note__: Specifications inside layer cannot use row and column channels as layering facet specifications is not allowed.
data (Data) An object describing the data source
description (string) Description of this mark for commenting purpose.
encoding (Encoding) A shared key-value mapping between encoding channels and definition of fields in the underlying layers.
height (float) The height of a visualization. __Default value:__ - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its y-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - For y-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the height is [determined by the range step, paddings, and the cardinality of the field mapped to y-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to y channel, the height will be the value of rangeStep. __Note__: For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the height of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
name (string) Name of the visualization for later reference.
projection (Projection) An object defining properties of the geographic projection shared by underlying layers.
resolve (Resolve) Scale, axis, and legend resolutions for layers.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
width (float) The width of a visualization. __Default value:__ This will be determined by the following rules: - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its x-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - For x-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the width is [determined by the range step, paddings, and the cardinality of the field mapped to x-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to x channel, the width will be the value of [config.scale.textXRangeStep](https://vega.github.io/vega-lite/docs/size.html#default-width-and-height) for text mark and the value of rangeStep for other marks. __Note:__ For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the width of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
class altair.Legend(entryPadding=Undefined, format=Undefined, offset=Undefined, orient=Undefined, padding=Undefined, tickCount=Undefined, title=Undefined, type=Undefined, values=Undefined, zindex=Undefined, **kwds)

Legend schema wrapper

Mapping(required=[]) Properties of a legend or boolean flag for determining whether to show it.

Attributes

entryPadding (float) Padding (in pixels) between legend entries in a symbol legend.
format (string) The formatting pattern for labels. This is D3’s [number format pattern](https://github.com/d3/d3-format#locale_format) for quantitative fields and D3’s [time format pattern](https://github.com/d3/d3-time-format#locale_format) for time field. See the [format documentation](format.html) for more information. __Default value:__ derived from [numberFormat](config.html#format) config for quantitative fields and from [timeFormat](config.html#format) config for temporal fields.
offset (float) The offset, in pixels, by which to displace the legend from the edge of the enclosing group or data rectangle. __Default value:__ 0
orient (LegendOrient) The orientation of the legend, which determines how the legend is positioned within the scene. One of “left”, “right”, “top-left”, “top-right”, “bottom-left”, “bottom-right”, “none”. __Default value:__ “right”
padding (float) The padding, in pixels, between the legend and axis.
tickCount (float) The desired number of tick values for quantitative legends.
title (anyOf(string, None)) A title for the field. If null, the title will be removed. __Default value:__ derived from the field’s name and transformation function (aggregate, bin and timeUnit). If the field has an aggregate function, the function is displayed as a part of the title (e.g., “Sum of Profit”). If the field is binned or has a time unit applied, the applied function will be denoted in parentheses (e.g., “Profit (binned)”, “Transaction Date (year-month)”). Otherwise, the title is simply the field name. __Note__: You can customize the default field title format by providing the [fieldTitle property in the [config](config.html) or [fieldTitle function via the compile function’s options](compile.html#field-title).
type (enum(‘symbol’, ‘gradient’)) The type of the legend. Use “symbol” to create a discrete legend and “gradient” for a continuous color gradient. __Default value:__ “gradient” for non-binned quantitative fields and temporal fields; “symbol” otherwise.
values (anyOf(List(float), List(string), List(DateTime))) Explicitly set the visible legend values.
zindex (float) A non-positive integer indicating z-index of the legend. If zindex is 0, legend should be drawn behind all chart elements. To put them in front, use zindex = 1.
class altair.LegendConfig(cornerRadius=Undefined, entryPadding=Undefined, fillColor=Undefined, gradientHeight=Undefined, gradientLabelBaseline=Undefined, gradientLabelLimit=Undefined, gradientLabelOffset=Undefined, gradientStrokeColor=Undefined, gradientStrokeWidth=Undefined, gradientWidth=Undefined, labelAlign=Undefined, labelBaseline=Undefined, labelColor=Undefined, labelFont=Undefined, labelFontSize=Undefined, labelLimit=Undefined, labelOffset=Undefined, offset=Undefined, orient=Undefined, padding=Undefined, shortTimeLabels=Undefined, strokeColor=Undefined, strokeDash=Undefined, strokeWidth=Undefined, symbolColor=Undefined, symbolSize=Undefined, symbolStrokeWidth=Undefined, symbolType=Undefined, titleAlign=Undefined, titleBaseline=Undefined, titleColor=Undefined, titleFont=Undefined, titleFontSize=Undefined, titleFontWeight=Undefined, titleLimit=Undefined, titlePadding=Undefined, **kwds)

LegendConfig schema wrapper

Mapping(required=[])

Attributes

cornerRadius (float) Corner radius for the full legend.
entryPadding (float) Padding (in pixels) between legend entries in a symbol legend.
fillColor (string) Background fill color for the full legend.
gradientHeight (float) The height of the gradient, in pixels.
gradientLabelBaseline (string) Text baseline for color ramp gradient labels.
gradientLabelLimit (float) The maximum allowed length in pixels of color ramp gradient labels.
gradientLabelOffset (float) Vertical offset in pixels for color ramp gradient labels.
gradientStrokeColor (string) The color of the gradient stroke, can be in hex color code or regular color name.
gradientStrokeWidth (float) The width of the gradient stroke, in pixels.
gradientWidth (float) The width of the gradient, in pixels.
labelAlign (string) The alignment of the legend label, can be left, middle or right.
labelBaseline (string) The position of the baseline of legend label, can be top, middle or bottom.
labelColor (string) The color of the legend label, can be in hex color code or regular color name.
labelFont (string) The font of the legend label.
labelFontSize (float) The font size of legend label. __Default value:__ 10.
labelLimit (float) Maximum allowed pixel width of axis tick labels.
labelOffset (float) The offset of the legend label.
offset (float) The offset, in pixels, by which to displace the legend from the edge of the enclosing group or data rectangle. __Default value:__ 0
orient (LegendOrient) The orientation of the legend, which determines how the legend is positioned within the scene. One of “left”, “right”, “top-left”, “top-right”, “bottom-left”, “bottom-right”, “none”. __Default value:__ “right”
padding (float) The padding, in pixels, between the legend and axis.
shortTimeLabels (boolean) Whether month names and weekday names should be abbreviated. __Default value:__ false
strokeColor (string) Border stroke color for the full legend.
strokeDash (List(float)) Border stroke dash pattern for the full legend.
strokeWidth (float) Border stroke width for the full legend.
symbolColor (string) The color of the legend symbol,
symbolSize (float) The size of the legend symbol, in pixels.
symbolStrokeWidth (float) The width of the symbol’s stroke.
symbolType (string) Default shape type (such as “circle”) for legend symbols.
titleAlign (string) Horizontal text alignment for legend titles.
titleBaseline (string) Vertical text baseline for legend titles.
titleColor (string) The color of the legend title, can be in hex color code or regular color name.
titleFont (string) The font of the legend title.
titleFontSize (float) The font size of the legend title.
titleFontWeight (FontWeight) The font weight of the legend title. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
titleLimit (float) Maximum allowed pixel width of axis titles.
titlePadding (float) The padding, in pixels, between title and legend.
class altair.LegendOrient(*args)

LegendOrient schema wrapper

enum(‘left’, ‘right’, ‘top-left’, ‘top-right’, ‘bottom-left’, ‘bottom-right’, ‘none’)

class altair.LegendResolveMap(color=Undefined, fill=Undefined, opacity=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, **kwds)

LegendResolveMap schema wrapper

Mapping(required=[])

Attributes

color (ResolveMode)
fill (ResolveMode)
opacity (ResolveMode)
shape (ResolveMode)
size (ResolveMode)
stroke (ResolveMode)
class altair.LocalMultiTimeUnit(*args)

LocalMultiTimeUnit schema wrapper

enum(‘yearquarter’, ‘yearquartermonth’, ‘yearmonth’, ‘yearmonthdate’, ‘yearmonthdatehours’, ‘yearmonthdatehoursminutes’, ‘yearmonthdatehoursminutesseconds’, ‘quartermonth’, ‘monthdate’, ‘hoursminutes’, ‘hoursminutesseconds’, ‘minutesseconds’, ‘secondsmilliseconds’)

class altair.LocalSingleTimeUnit(*args)

LocalSingleTimeUnit schema wrapper

enum(‘year’, ‘quarter’, ‘month’, ‘day’, ‘date’, ‘hours’, ‘minutes’, ‘seconds’, ‘milliseconds’)

class altair.LogicalAndPredicate(**kwds)

LogicalAndPredicate schema wrapper

Mapping(required=[and])

class altair.LogicalNotPredicate(**kwds)

LogicalNotPredicate schema wrapper

Mapping(required=[not])

class altair.LogicalOperandPredicate(*args, **kwds)

LogicalOperandPredicate schema wrapper

anyOf(LogicalNotPredicate, LogicalAndPredicate, LogicalOrPredicate, Predicate)

class altair.LogicalOrPredicate(**kwds)

LogicalOrPredicate schema wrapper

Mapping(required=[or])

class altair.Longitude(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Longitude schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Longitude2(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Longitude2 schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.LookupData(data=Undefined, key=Undefined, fields=Undefined, **kwds)

LookupData schema wrapper

Mapping(required=[data, key])

Attributes

data (Data) Secondary data source to lookup in.
key (string) Key in data to lookup.
fields (List(string)) Fields in foreign data to lookup. If not specified, the entire object is queried.
to_dict(*args, **kwargs)

Convert the chart to a dictionary suitable for JSON export

class altair.LookupTransform(lookup=Undefined, default=Undefined, **kwds)

LookupTransform schema wrapper

Mapping(required=[lookup, from])

Attributes

lookup (string) Key in primary data source.
default (string) The default value to use if lookup fails. __Default value:__ null
class altair.Mark(*args)

Mark schema wrapper

enum(‘area’, ‘bar’, ‘line’, ‘point’, ‘text’, ‘tick’, ‘rect’, ‘rule’, ‘circle’, ‘square’, ‘geoshape’) All types of primitive marks.

class altair.MarkConfig(align=Undefined, angle=Undefined, baseline=Undefined, color=Undefined, cursor=Undefined, dx=Undefined, dy=Undefined, fill=Undefined, fillOpacity=Undefined, filled=Undefined, font=Undefined, fontSize=Undefined, fontStyle=Undefined, fontWeight=Undefined, href=Undefined, interpolate=Undefined, limit=Undefined, opacity=Undefined, orient=Undefined, radius=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, strokeDash=Undefined, strokeDashOffset=Undefined, strokeOpacity=Undefined, strokeWidth=Undefined, tension=Undefined, text=Undefined, theta=Undefined, **kwds)

MarkConfig schema wrapper

Mapping(required=[])

Attributes

align (HorizontalAlign) The horizontal alignment of the text. One of “left”, “right”, “center”.
angle (float) The rotation angle of the text, in degrees.
baseline (VerticalAlign) The vertical alignment of the text. One of “top”, “middle”, “bottom”. __Default value:__ “middle”
color (string) Default color. Note that fill and stroke have higher precedence than color and will override color. __Default value:__ <span style=”color: #4682b4;”>&#9632;</span> “#4682b4” __Note:__ This property cannot be used in a [style config](mark.html#style-config).
cursor (enum(‘auto’, ‘default’, ‘none’, ‘context-menu’, ‘help’, ‘pointer’, ‘progress’,)
‘wait’, ‘cell’, ‘crosshair’, ‘text’, ‘vertical-text’, ‘alias’, ‘copy’, ‘move’, ‘no-drop’,  
‘not-allowed’, ‘e-resize’, ‘n-resize’, ‘ne-resize’, ‘nw-resize’, ‘s-resize’, ‘se-resize’,  
‘sw-resize’, ‘w-resize’, ‘ew-resize’, ‘ns-resize’, ‘nesw-resize’, ‘nwse-resize’,  
‘col-resize’, ‘row-resize’, ‘all-scroll’, ‘zoom-in’, ‘zoom-out’, ‘grab’, ‘grabbing’) The mouse cursor used over the mark. Any valid [CSS cursor type](https://developer.mozilla.org/en-US/docs/Web/CSS/cursor#Values) can be used.
dx (float) The horizontal offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
dy (float) The vertical offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
fill (string) Default Fill Color. This has higher precedence than config.color __Default value:__ (None)
fillOpacity (float) The fill opacity (value between [0,1]). __Default value:__ 1
filled (boolean) Whether the mark’s color should be used as fill color instead of stroke color. __Default value:__ true for all marks except point and false for point. __Applicable for:__ bar, point, circle, square, and area marks. __Note:__ This property cannot be used in a [style config](mark.html#style-config).
font (string) The typeface to set the text in (e.g., “Helvetica Neue”).
fontSize (float) The font size, in pixels.
fontStyle (FontStyle) The font style (e.g., “italic”).
fontWeight (FontWeight) The font weight. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
href (string) A URL to load upon mouse click. If defined, the mark acts as a hyperlink.
interpolate (Interpolate) The line interpolation method to use for line and area marks. One of the following: - “linear”: piecewise linear segments, as in a polyline. - “linear-closed”: close the linear segments to form a polygon. - “step”: alternate between horizontal and vertical segments, as in a step function. - “step-before”: alternate between vertical and horizontal segments, as in a step function. - “step-after”: alternate between horizontal and vertical segments, as in a step function. - “basis”: a B-spline, with control point duplication on the ends. - “basis-open”: an open B-spline; may not intersect the start or end. - “basis-closed”: a closed B-spline, as in a loop. - “cardinal”: a Cardinal spline, with control point duplication on the ends. - “cardinal-open”: an open Cardinal spline; may not intersect the start or end, but will intersect other control points. - “cardinal-closed”: a closed Cardinal spline, as in a loop. - “bundle”: equivalent to basis, except the tension parameter is used to straighten the spline. - “monotone”: cubic interpolation that preserves monotonicity in y.
limit (float) The maximum length of the text mark in pixels (default 0, indicating no limit). The text value will be automatically truncated if the rendered size exceeds the limit.
opacity (float) The overall opacity (value between [0,1]). __Default value:__ 0.7 for non-aggregate plots with point, tick, circle, or square marks or layered bar charts and 1 otherwise.
orient (Orient) The orientation of a non-stacked bar, tick, area, and line charts. The value is either horizontal (default) or vertical. - For bar, rule and tick, this determines whether the size of the bar and tick should be applied to x or y dimension. - For area, this property determines the orient property of the Vega output. - For line, this property determines the sort order of the points in the line if config.sortLineBy is not specified. For stacked charts, this is always determined by the orientation of the stack; therefore explicitly specified value will be ignored.
radius (float) Polar coordinate radial offset, in pixels, of the text label from the origin determined by the x and y properties.
shape (string) The default symbol shape to use. One of: “circle” (default), “square”, “cross”, “diamond”, “triangle-up”, or “triangle-down”, or a custom SVG path. __Default value:__ “circle”
size (float) The pixel area each the point/circle/square. For example: in the case of circles, the radius is determined in part by the square root of the size value. __Default value:__ 30
stroke (string) Default Stroke Color. This has higher precedence than config.color __Default value:__ (None)
strokeDash (List(float)) An array of alternating stroke, space lengths for creating dashed or dotted lines.
strokeDashOffset (float) The offset (in pixels) into which to begin drawing with the stroke dash array.
strokeOpacity (float) The stroke opacity (value between [0,1]). __Default value:__ 1
strokeWidth (float) The stroke width, in pixels.
tension (float) Depending on the interpolation type, sets the tension parameter (for line and area marks).
text (string) Placeholder text if the text channel is not specified
theta (float) Polar coordinate angle, in radians, of the text label from the origin determined by the x and y properties. Values for theta follow the same convention of arc mark startAngle and endAngle properties: angles are measured in radians, with 0 indicating “north”.
class altair.MarkDef(type=Undefined, align=Undefined, angle=Undefined, baseline=Undefined, clip=Undefined, color=Undefined, cursor=Undefined, dx=Undefined, dy=Undefined, fill=Undefined, fillOpacity=Undefined, filled=Undefined, font=Undefined, fontSize=Undefined, fontStyle=Undefined, fontWeight=Undefined, href=Undefined, interpolate=Undefined, limit=Undefined, opacity=Undefined, orient=Undefined, radius=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, strokeDash=Undefined, strokeDashOffset=Undefined, strokeOpacity=Undefined, strokeWidth=Undefined, style=Undefined, tension=Undefined, text=Undefined, theta=Undefined, **kwds)

MarkDef schema wrapper

Mapping(required=[type])

Attributes

type (Mark) The mark type. One of “bar”, “circle”, “square”, “tick”, “line”, “area”, “point”, “geoshape”, “rule”, and “text”.
align (HorizontalAlign) The horizontal alignment of the text. One of “left”, “right”, “center”.
angle (float) The rotation angle of the text, in degrees.
baseline (VerticalAlign) The vertical alignment of the text. One of “top”, “middle”, “bottom”. __Default value:__ “middle”
clip (boolean) Whether a mark be clipped to the enclosing group’s width and height.
color (string) Default color. Note that fill and stroke have higher precedence than color and will override color. __Default value:__ <span style=”color: #4682b4;”>&#9632;</span> “#4682b4” __Note:__ This property cannot be used in a [style config](mark.html#style-config).
cursor (enum(‘auto’, ‘default’, ‘none’, ‘context-menu’, ‘help’, ‘pointer’, ‘progress’,)
‘wait’, ‘cell’, ‘crosshair’, ‘text’, ‘vertical-text’, ‘alias’, ‘copy’, ‘move’, ‘no-drop’,  
‘not-allowed’, ‘e-resize’, ‘n-resize’, ‘ne-resize’, ‘nw-resize’, ‘s-resize’, ‘se-resize’,  
‘sw-resize’, ‘w-resize’, ‘ew-resize’, ‘ns-resize’, ‘nesw-resize’, ‘nwse-resize’,  
‘col-resize’, ‘row-resize’, ‘all-scroll’, ‘zoom-in’, ‘zoom-out’, ‘grab’, ‘grabbing’) The mouse cursor used over the mark. Any valid [CSS cursor type](https://developer.mozilla.org/en-US/docs/Web/CSS/cursor#Values) can be used.
dx (float) The horizontal offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
dy (float) The vertical offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
fill (string) Default Fill Color. This has higher precedence than config.color __Default value:__ (None)
fillOpacity (float) The fill opacity (value between [0,1]). __Default value:__ 1
filled (boolean) Whether the mark’s color should be used as fill color instead of stroke color. __Default value:__ true for all marks except point and false for point. __Applicable for:__ bar, point, circle, square, and area marks. __Note:__ This property cannot be used in a [style config](mark.html#style-config).
font (string) The typeface to set the text in (e.g., “Helvetica Neue”).
fontSize (float) The font size, in pixels.
fontStyle (FontStyle) The font style (e.g., “italic”).
fontWeight (FontWeight) The font weight. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
href (string) A URL to load upon mouse click. If defined, the mark acts as a hyperlink.
interpolate (Interpolate) The line interpolation method to use for line and area marks. One of the following: - “linear”: piecewise linear segments, as in a polyline. - “linear-closed”: close the linear segments to form a polygon. - “step”: alternate between horizontal and vertical segments, as in a step function. - “step-before”: alternate between vertical and horizontal segments, as in a step function. - “step-after”: alternate between horizontal and vertical segments, as in a step function. - “basis”: a B-spline, with control point duplication on the ends. - “basis-open”: an open B-spline; may not intersect the start or end. - “basis-closed”: a closed B-spline, as in a loop. - “cardinal”: a Cardinal spline, with control point duplication on the ends. - “cardinal-open”: an open Cardinal spline; may not intersect the start or end, but will intersect other control points. - “cardinal-closed”: a closed Cardinal spline, as in a loop. - “bundle”: equivalent to basis, except the tension parameter is used to straighten the spline. - “monotone”: cubic interpolation that preserves monotonicity in y.
limit (float) The maximum length of the text mark in pixels (default 0, indicating no limit). The text value will be automatically truncated if the rendered size exceeds the limit.
opacity (float) The overall opacity (value between [0,1]). __Default value:__ 0.7 for non-aggregate plots with point, tick, circle, or square marks or layered bar charts and 1 otherwise.
orient (Orient) The orientation of a non-stacked bar, tick, area, and line charts. The value is either horizontal (default) or vertical. - For bar, rule and tick, this determines whether the size of the bar and tick should be applied to x or y dimension. - For area, this property determines the orient property of the Vega output. - For line, this property determines the sort order of the points in the line if config.sortLineBy is not specified. For stacked charts, this is always determined by the orientation of the stack; therefore explicitly specified value will be ignored.
radius (float) Polar coordinate radial offset, in pixels, of the text label from the origin determined by the x and y properties.
shape (string) The default symbol shape to use. One of: “circle” (default), “square”, “cross”, “diamond”, “triangle-up”, or “triangle-down”, or a custom SVG path. __Default value:__ “circle”
size (float) The pixel area each the point/circle/square. For example: in the case of circles, the radius is determined in part by the square root of the size value. __Default value:__ 30
stroke (string) Default Stroke Color. This has higher precedence than config.color __Default value:__ (None)
strokeDash (List(float)) An array of alternating stroke, space lengths for creating dashed or dotted lines.
strokeDashOffset (float) The offset (in pixels) into which to begin drawing with the stroke dash array.
strokeOpacity (float) The stroke opacity (value between [0,1]). __Default value:__ 1
strokeWidth (float) The stroke width, in pixels.
style (anyOf(string, List(string))) A string or array of strings indicating the name of custom styles to apply to the mark. A style is a named collection of mark property defaults defined within the [style configuration](mark.html#style-config). If style is an array, later styles will override earlier styles. Any [mark properties](encoding.html#mark-prop) explicitly defined within the encoding will override a style default. __Default value:__ The mark’s name. For example, a bar mark will have style “bar” by default. __Note:__ Any specified style will augment the default style. For example, a bar mark with “style”: “foo” will receive from config.style.bar and config.style.foo (the specified style “foo” has higher precedence).
tension (float) Depending on the interpolation type, sets the tension parameter (for line and area marks).
text (string) Placeholder text if the text channel is not specified
theta (float) Polar coordinate angle, in radians, of the text label from the origin determined by the x and y properties. Values for theta follow the same convention of arc mark startAngle and endAngle properties: angles are measured in radians, with 0 indicating “north”.
class altair.MarkPropFieldDefWithCondition(type=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, **kwds)

MarkPropFieldDefWithCondition schema wrapper

Mapping(required=[type]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.MarkPropValueDefWithCondition(condition=Undefined, value=Undefined, **kwds)

MarkPropValueDefWithCondition schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Month(*args)

Month schema wrapper

float

class altair.MultiSelection(type=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, nearest=Undefined, on=Undefined, resolve=Undefined, toggle=Undefined, **kwds)

MultiSelection schema wrapper

Mapping(required=[type])

Attributes

type (enum(‘multi’))
empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
nearest (boolean) When true, an invisible voronoi diagram is computed to accelerate discrete selection. The data value _nearest_ the mouse cursor is added to the selection. See the [nearest transform](nearest.html) documentation for more information.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
toggle (anyOf(string, boolean)) Controls whether data values should be toggled or only ever inserted into multi selections. Can be true, false (for insertion only), or a [Vega expression](https://vega.github.io/vega/docs/expressions/). __Default value:__ true, which corresponds to event.shiftKey (i.e., data values are toggled when a user interacts with the shift-key pressed). See the [toggle transform](toggle.html) documentation for more information.
class altair.MultiSelectionConfig(empty=Undefined, encodings=Undefined, fields=Undefined, nearest=Undefined, on=Undefined, resolve=Undefined, toggle=Undefined, **kwds)

MultiSelectionConfig schema wrapper

Mapping(required=[])

Attributes

empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
nearest (boolean) When true, an invisible voronoi diagram is computed to accelerate discrete selection. The data value _nearest_ the mouse cursor is added to the selection. See the [nearest transform](nearest.html) documentation for more information.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
toggle (anyOf(string, boolean)) Controls whether data values should be toggled or only ever inserted into multi selections. Can be true, false (for insertion only), or a [Vega expression](https://vega.github.io/vega/docs/expressions/). __Default value:__ true, which corresponds to event.shiftKey (i.e., data values are toggled when a user interacts with the shift-key pressed). See the [toggle transform](toggle.html) documentation for more information.
class altair.MultiTimeUnit(*args, **kwds)

MultiTimeUnit schema wrapper

anyOf(LocalMultiTimeUnit, UtcMultiTimeUnit)

class altair.NamedData(name=Undefined, format=Undefined, **kwds)

NamedData schema wrapper

Mapping(required=[name])

Attributes

name (string) Provide a placeholder name and bind data at runtime.
format (DataFormat) An object that specifies the format for parsing the data.
class altair.NamedSelection(*args, **kwds)

A SelectionMapping with a single named selection item

ref()

Return a selection reference to this object

Examples

>>> import altair as alt
>>> sel = alt.selection_interval(name='interval')
>>> sel.ref()
{'selection': 'interval'}
class altair.NiceTime(*args)

NiceTime schema wrapper

enum(‘second’, ‘minute’, ‘hour’, ‘day’, ‘week’, ‘month’, ‘year’)

class altair.Opacity(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Opacity schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.OpacityValue(value, condition=Undefined, **kwds)

OpacityValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.Order(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Order schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
sort (SortOrder) The sort order. One of “ascending” (default) or “descending”.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.OrderFieldDef(type=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, sort=Undefined, timeUnit=Undefined, **kwds)

OrderFieldDef schema wrapper

Mapping(required=[type])

Attributes

type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
sort (SortOrder) The sort order. One of “ascending” (default) or “descending”.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.Orient(*args)

Orient schema wrapper

enum(‘horizontal’, ‘vertical’)

class altair.Padding(*args, **kwds)

Padding schema wrapper

anyOf(float, Mapping(required=[]))

class altair.PositionFieldDef(type=Undefined, aggregate=Undefined, axis=Undefined, bin=Undefined, field=Undefined, scale=Undefined, sort=Undefined, stack=Undefined, timeUnit=Undefined, **kwds)

PositionFieldDef schema wrapper

Mapping(required=[type])

Attributes

type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
axis (anyOf(Axis, None)) An object defining properties of axis’s gridlines, ticks and labels. If null, the axis for the encoding channel will be removed. __Default value:__ If undefined, default [axis properties](https://vega.github.io/vega-lite/docs/axis.html) are applied.
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
stack (anyOf(StackOffset, None)) Type of stacking offset if the field should be stacked. stack is only applicable for x and y channels with continuous domains. For example, stack of y can be used to customize stacking for a vertical bar chart. stack can be one of the following values: - “zero”: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart). - “normalize” - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/> -“center” - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)). - null - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart. __Default value:__ zero for plots with all of the following conditions are true: (1) the mark is bar or area; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, null by default.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.Predicate(*args, **kwds)

Predicate schema wrapper

anyOf(FieldEqualPredicate, FieldRangePredicate, FieldOneOfPredicate, SelectionPredicate, string)

class altair.Projection(center=Undefined, clipAngle=Undefined, clipExtent=Undefined, coefficient=Undefined, distance=Undefined, fraction=Undefined, lobes=Undefined, parallel=Undefined, precision=Undefined, radius=Undefined, ratio=Undefined, rotate=Undefined, spacing=Undefined, tilt=Undefined, type=Undefined, **kwds)

Projection schema wrapper

Mapping(required=[])

Attributes

center (List(float)) Sets the projection’s center to the specified center, a two-element array of longitude and latitude in degrees. __Default value:__ [0, 0]
clipAngle (float) Sets the projection’s clipping circle radius to the specified angle in degrees. If null, switches to [antimeridian](http://bl.ocks.org/mbostock/3788999) cutting rather than small-circle clipping.
clipExtent (List(List(float))) Sets the projection’s viewport clip extent to the specified bounds in pixels. The extent bounds are specified as an array [[x0, y0], [x1, y1]], where x0 is the left-side of the viewport, y0 is the top, x1 is the right and y1 is the bottom. If null, no viewport clipping is performed.
coefficient (float)
distance (float)
fraction (float)
lobes (float)
parallel (float)
precision (Mapping(required=[length])) Sets the threshold for the projection’s [adaptive resampling](http://bl.ocks.org/mbostock/3795544) to the specified value in pixels. This value corresponds to the [Douglas–Peucker distance](http://en.wikipedia.org/wiki/Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm). If precision is not specified, returns the projection’s current resampling precision which defaults to √0.5 ≅ 0.70710….
radius (float)
ratio (float)
rotate (List(float)) Sets the projection’s three-axis rotation to the specified angles, which must be a two- or three-element array of numbers [lambda, phi, gamma] specifying the rotation angles in degrees about each spherical axis. (These correspond to yaw, pitch and roll.) __Default value:__ [0, 0, 0]
spacing (float)
tilt (float)
type (ProjectionType) The cartographic projection to use. This value is case-insensitive, for example “albers” and “Albers” indicate the same projection type. You can find all valid projection types [in the documentation](https://vega.github.io/vega-lite/docs/projection.html#projection-types). __Default value:__ mercator
class altair.ProjectionConfig(center=Undefined, clipAngle=Undefined, clipExtent=Undefined, coefficient=Undefined, distance=Undefined, fraction=Undefined, lobes=Undefined, parallel=Undefined, precision=Undefined, radius=Undefined, ratio=Undefined, rotate=Undefined, spacing=Undefined, tilt=Undefined, type=Undefined, **kwds)

ProjectionConfig schema wrapper

Mapping(required=[]) Any property of Projection can be in config

Attributes

center (List(float)) Sets the projection’s center to the specified center, a two-element array of longitude and latitude in degrees. __Default value:__ [0, 0]
clipAngle (float) Sets the projection’s clipping circle radius to the specified angle in degrees. If null, switches to [antimeridian](http://bl.ocks.org/mbostock/3788999) cutting rather than small-circle clipping.
clipExtent (List(List(float))) Sets the projection’s viewport clip extent to the specified bounds in pixels. The extent bounds are specified as an array [[x0, y0], [x1, y1]], where x0 is the left-side of the viewport, y0 is the top, x1 is the right and y1 is the bottom. If null, no viewport clipping is performed.
coefficient (float)
distance (float)
fraction (float)
lobes (float)
parallel (float)
precision (Mapping(required=[length])) Sets the threshold for the projection’s [adaptive resampling](http://bl.ocks.org/mbostock/3795544) to the specified value in pixels. This value corresponds to the [Douglas–Peucker distance](http://en.wikipedia.org/wiki/Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm). If precision is not specified, returns the projection’s current resampling precision which defaults to √0.5 ≅ 0.70710….
radius (float)
ratio (float)
rotate (List(float)) Sets the projection’s three-axis rotation to the specified angles, which must be a two- or three-element array of numbers [lambda, phi, gamma] specifying the rotation angles in degrees about each spherical axis. (These correspond to yaw, pitch and roll.) __Default value:__ [0, 0, 0]
spacing (float)
tilt (float)
type (ProjectionType) The cartographic projection to use. This value is case-insensitive, for example “albers” and “Albers” indicate the same projection type. You can find all valid projection types [in the documentation](https://vega.github.io/vega-lite/docs/projection.html#projection-types). __Default value:__ mercator
class altair.ProjectionType(*args)

ProjectionType schema wrapper

enum(‘albers’, ‘albersUsa’, ‘azimuthalEqualArea’, ‘azimuthalEquidistant’, ‘conicConformal’, ‘conicEqualArea’, ‘conicEquidistant’, ‘equirectangular’, ‘gnomonic’, ‘mercator’, ‘orthographic’, ‘stereographic’, ‘transverseMercator’)

class altair.RangeConfig(category=Undefined, diverging=Undefined, heatmap=Undefined, ordinal=Undefined, ramp=Undefined, symbol=Undefined, **kwds)

RangeConfig schema wrapper

Mapping(required=[])

Attributes

category (anyOf(List(string), VgScheme)) Default range for _nominal_ (categorical) fields.
diverging (anyOf(List(string), VgScheme)) Default range for diverging _quantitative_ fields.
heatmap (anyOf(List(string), VgScheme)) Default range for _quantitative_ heatmaps.
ordinal (anyOf(List(string), VgScheme)) Default range for _ordinal_ fields.
ramp (anyOf(List(string), VgScheme)) Default range for _quantitative_ and _temporal_ fields.
symbol (List(string)) Default range palette for the shape channel.
class altair.RangeConfigValue(*args, **kwds)

RangeConfigValue schema wrapper

anyOf(List(anyOf(float, string)), VgScheme, Mapping(required=[step]))

class altair.Repeat(column=Undefined, row=Undefined, **kwds)

Repeat schema wrapper

Mapping(required=[])

Attributes

column (List(string)) Horizontal repeated views.
row (List(string)) Vertical repeated views.
class altair.RepeatChart(spec=Undefined, data=Undefined, repeat=Undefined, **kwargs)

A chart repeated across rows and columns with small changes Mapping(required=[repeat, spec])

Attributes

repeat([row, column]) Return a RepeatChart built from the chart
spec (Spec)
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale and legend resolutions for repeated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
interactive(name=None, bind_x=True, bind_y=True)

Make chart axes scales interactive

Parameters:

name : string

The selection name to use for the axes scales. This name should be unique among all selections within the chart.

bind_x : boolean, default True

If true, then bind the interactive scales to the x-axis

bind_y : boolean, default True

If true, then bind the interactive scales to the y-axis

Returns:

chart :

copy of self, with interactive axes added

class altair.RepeatRef(repeat=Undefined, **kwds)

RepeatRef schema wrapper

Mapping(required=[repeat]) Reference to a repeated value.

Attributes

repeat (enum(‘row’, ‘column’))
class altair.RepeatSpec(repeat=Undefined, spec=Undefined, data=Undefined, description=Undefined, name=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, **kwds)

RepeatSpec schema wrapper

Mapping(required=[repeat, spec])

Attributes

repeat (Repeat) An object that describes what fields should be repeated into views that are laid out as a row or column.
spec (Spec)
data (Data) An object describing the data source
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
resolve (Resolve) Scale and legend resolutions for repeated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.Resolve(axis=Undefined, legend=Undefined, scale=Undefined, **kwds)

Resolve schema wrapper

Mapping(required=[]) Defines how scales, axes, and legends from different specs should be combined. Resolve is a mapping from scale, axis, and legend to a mapping from channels to resolutions.

Attributes

axis (AxisResolveMap)
legend (LegendResolveMap)
scale (ScaleResolveMap)
class altair.ResolveMode(*args)

ResolveMode schema wrapper

enum(‘independent’, ‘shared’)

class altair.Root(*args, **kwds)

Root schema wrapper

anyOf(TopLevelFacetedUnitSpec, TopLevelFacetSpec, TopLevelLayerSpec, TopLevelRepeatSpec, TopLevelVConcatSpec, TopLevelHConcatSpec)

class altair.Row(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, header=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Row schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
header (Header) An object defining properties of a facet’s header.
sort (SortOrder) Sort order for a facet field. This can be “ascending”, “descending”.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Scale(base=Undefined, clamp=Undefined, domain=Undefined, exponent=Undefined, interpolate=Undefined, nice=Undefined, padding=Undefined, paddingInner=Undefined, paddingOuter=Undefined, range=Undefined, rangeStep=Undefined, round=Undefined, scheme=Undefined, type=Undefined, zero=Undefined, **kwds)

Scale schema wrapper

Mapping(required=[])

Attributes

base (float) The logarithm base of the log scale (default 10).
clamp (boolean) If true, values that exceed the data domain are clamped to either the minimum or maximum range value __Default value:__ derived from the [scale config](config.html#scale-config)’s clamp (true by default).
domain (anyOf(List(float), List(string), List(boolean), List(DateTime),)
enum(‘unaggregated’), SelectionDomain) Customized domain values. For _quantitative_ fields, domain can take the form of a two-element array with minimum and maximum values. [Piecewise scales](scale.html#piecewise) can be created by providing a domain with more than two entries. If the input field is aggregated, domain can also be a string value “unaggregated”, indicating that the domain should include the raw data values prior to the aggregation. For _temporal_ fields, domain can be a two-element array minimum and maximum values, in the form of either timestamps or the [DateTime definition objects](types.html#datetime). For _ordinal_ and _nominal_ fields, domain can be an array that lists valid input values. The selection property can be used to [interactively determine](selection.html#scale-domains) the scale domain.
exponent (float) The exponent of the pow scale.
interpolate (anyOf(ScaleInterpolate, ScaleInterpolateParams)) The interpolation method for range values. By default, a general interpolator for numbers, dates, strings and colors (in RGB space) is used. For color ranges, this property allows interpolation in alternative color spaces. Legal values include rgb, hsl, hsl-long, lab, hcl, hcl-long, cubehelix and cubehelix-long (‘-long’ variants use longer paths in polar coordinate spaces). If object-valued, this property accepts an object with a string-valued _type_ property and an optional numeric _gamma_ property applicable to rgb and cubehelix interpolators. For more, see the [d3-interpolate documentation](https://github.com/d3/d3-interpolate). __Note:__ Sequential scales do not support interpolate as they have a fixed interpolator. Since Vega-Lite uses sequential scales for quantitative fields by default, you have to set the scale type to other quantitative scale type such as “linear” to customize interpolate.
nice (anyOf(boolean, float, NiceTime, Mapping(required=[interval, step]))) Extending the domain so that it starts and ends on nice round values. This method typically modifies the scale’s domain, and may only extend the bounds to the nearest round value. Nicing is useful if the domain is computed from data and may be irregular. For example, for a domain of _[0.201479…, 0.996679…]_, a nice domain might be _[0.2, 1.0]_. For quantitative scales such as linear, nice can be either a boolean flag or a number. If nice is a number, it will represent a desired tick count. This allows greater control over the step size used to extend the bounds, guaranteeing that the returned ticks will exactly cover the domain. For temporal fields with time and utc scales, the nice value can be a string indicating the desired time interval. Legal values are “millisecond”, “second”, “minute”, “hour”, “day”, “week”, “month”, and “year”. Alternatively, time and utc scales can accept an object-valued interval specifier of the form {“interval”: “month”, “step”: 3}, which includes a desired number of interval steps. Here, the domain would snap to quarter (Jan, Apr, Jul, Oct) boundaries. __Default value:__ true for unbinned _quantitative_ fields; false otherwise.
padding (float) For _[continuous](scale.html#continuous)_ scales, expands the scale domain to accommodate the specified number of pixels on each of the scale range. The scale range must represent pixels for this parameter to function as intended. Padding adjustment is performed prior to all other adjustments, including the effects of the zero, nice, domainMin, and domainMax properties. For _[band](scale.html#band)_ scales, shortcut for setting paddingInner and paddingOuter to the same value. For _[point](scale.html#point)_ scales, alias for paddingOuter. __Default value:__ For _continuous_ scales, derived from the [scale config](scale.html#config)’s continuousPadding. For _band and point_ scales, see paddingInner and paddingOuter.
paddingInner (float) The inner padding (spacing) within each band step of band scales, as a fraction of the step size. This value must lie in the range [0,1]. For point scale, this property is invalid as point scales do not have internal band widths (only step sizes between bands). __Default value:__ derived from the [scale config](scale.html#config)’s bandPaddingInner.
paddingOuter (float) The outer padding (spacing) at the ends of the range of band and point scales, as a fraction of the step size. This value must lie in the range [0,1]. __Default value:__ derived from the [scale config](scale.html#config)’s bandPaddingOuter for band scales and pointPadding for point scales.
range (anyOf(List(float), List(string), string)) The range of the scale. One of: - A string indicating a [pre-defined named scale range](scale.html#range-config) (e.g., example, “symbol”, or “diverging”). - For [continuous scales](scale.html#continuous), two-element array indicating minimum and maximum values, or an array with more than two entries for specifying a [piecewise scale](scale.html#piecewise). - For [discrete](scale.html#discrete) and [discretizing](scale.html#discretizing) scales, an array of desired output values. __Notes:__ 1) For [sequential](scale.html#sequential), [ordinal](scale.html#ordinal), and discretizing color scales, you can also specify a color [scheme](scale.html#scheme) instead of range. 2) Any directly specified range for x and y channels will be ignored. Range can be customized via the view’s corresponding [size](size.html) (width and height) or via [range steps and paddings properties](#range-step) for [band](#band) and [point](#point) scales.
rangeStep (anyOf(float, None)) The distance between the starts of adjacent bands or points in [band](scale.html#band) and [point](scale.html#point) scales. If rangeStep is null or if the view contains the scale’s corresponding [size](size.html) (width for x scales and height for y scales), rangeStep will be automatically determined to fit the size of the view. __Default value:__ derived the [scale config](config.html#scale-config)’s textXRangeStep (90 by default) for x-scales of text marks and rangeStep (21 by default) for x-scales of other marks and y-scales. __Warning__: If rangeStep is null and the cardinality of the scale’s domain is higher than width or height, the rangeStep might become less than one pixel and the mark might not appear correctly.
round (boolean) If true, rounds numeric output values to integers. This can be helpful for snapping to the pixel grid. __Default value:__ false.
scheme (anyOf(string, SchemeParams)) A string indicating a color [scheme](scale.html#scheme) name (e.g., “category10” or “viridis”) or a [scheme parameter object](scale.html#scheme-params). Discrete color schemes may be used with [discrete](scale.html#discrete) or [discretizing](scale.html#discretizing) scales. Continuous color schemes are intended for use with [sequential](scales.html#sequential) scales. For the full list of supported scheme, please refer to the [Vega Scheme](https://vega.github.io/vega/docs/schemes/#reference) reference.
type (ScaleType) The type of scale. Vega-Lite supports the following categories of scale types: 1) [Continuous Scales](scale.html#continuous) – mapping continuous domains to continuous output ranges ([“linear”](scale.html#linear), [“pow”](scale.html#pow), [“sqrt”](scale.html#sqrt), [“log”](scale.html#log), [“time”](scale.html#time), [“utc”](scale.html#utc), [“sequential”](scale.html#sequential)). 2) [Discrete Scales](scale.html#discrete) – mapping discrete domains to discrete ([“ordinal”](scale.html#ordinal)) or continuous ([“band”](scale.html#band) and [“point”](scale.html#point)) output ranges. 3) [Discretizing Scales](scale.html#discretizing) – mapping continuous domains to discrete output ranges ([“bin-linear”](scale.html#bin-linear) and [“bin-ordinal”](scale.html#bin-ordinal)). __Default value:__ please see the [scale type table](scale.html#type).
zero (boolean) If true, ensures that a zero baseline value is included in the scale domain. __Default value:__ true for x and y channels if the quantitative field is not binned and no custom domain is provided; false otherwise. __Note:__ Log, time, and utc scales do not support zero.
class altair.ScaleConfig(bandPaddingInner=Undefined, bandPaddingOuter=Undefined, clamp=Undefined, continuousPadding=Undefined, maxBandSize=Undefined, maxFontSize=Undefined, maxOpacity=Undefined, maxSize=Undefined, maxStrokeWidth=Undefined, minBandSize=Undefined, minFontSize=Undefined, minOpacity=Undefined, minSize=Undefined, minStrokeWidth=Undefined, pointPadding=Undefined, rangeStep=Undefined, round=Undefined, textXRangeStep=Undefined, useUnaggregatedDomain=Undefined, **kwds)

ScaleConfig schema wrapper

Mapping(required=[])

Attributes

bandPaddingInner (float) Default inner padding for x and y band-ordinal scales. __Default value:__ 0.1
bandPaddingOuter (float) Default outer padding for x and y band-ordinal scales. If not specified, by default, band scale’s paddingOuter is paddingInner/2.
clamp (boolean) If true, values that exceed the data domain are clamped to either the minimum or maximum range value
continuousPadding (float) Default padding for continuous scales. __Default:__ 5 for continuous x-scale of a vertical bar and continuous y-scale of a horizontal bar.; 0 otherwise.
maxBandSize (float) The default max value for mapping quantitative fields to bar’s size/bandSize. If undefined (default), we will use the scale’s rangeStep - 1.
maxFontSize (float) The default max value for mapping quantitative fields to text’s size/fontSize. __Default value:__ 40
maxOpacity (float) Default max opacity for mapping a field to opacity. __Default value:__ 0.8
maxSize (float) Default max value for point size scale.
maxStrokeWidth (float) Default max strokeWidth for strokeWidth (or rule/line’s size) scale. __Default value:__ 4
minBandSize (float) The default min value for mapping quantitative fields to bar and tick’s size/bandSize scale with zero=false. __Default value:__ 2
minFontSize (float) The default min value for mapping quantitative fields to tick’s size/fontSize scale with zero=false __Default value:__ 8
minOpacity (float) Default minimum opacity for mapping a field to opacity. __Default value:__ 0.3
minSize (float) Default minimum value for point size scale with zero=false. __Default value:__ 9
minStrokeWidth (float) Default minimum strokeWidth for strokeWidth (or rule/line’s size) scale with zero=false. __Default value:__ 1
pointPadding (float) Default outer padding for x and y point-ordinal scales. __Default value:__ 0.5
rangeStep (anyOf(float, None)) Default range step for band and point scales of (1) the y channel and (2) the x channel when the mark is not text. __Default value:__ 21
round (boolean) If true, rounds numeric output values to integers. This can be helpful for snapping to the pixel grid. (Only available for x, y, and size scales.)
textXRangeStep (float) Default range step for x band and point scales of text marks. __Default value:__ 90
useUnaggregatedDomain (boolean) Use the source data range before aggregation as scale domain instead of aggregated data for aggregate axis. This is equivalent to setting domain to “unaggregate” for aggregated _quantitative_ fields by default. This property only works with aggregate functions that produce values within the raw data domain (“mean”, “average”, “median”, “q1”, “q3”, “min”, “max”). For other aggregations that produce values outside of the raw data domain (e.g. “count”, “sum”), this property is ignored. __Default value:__ false
class altair.ScaleInterpolate(*args)

ScaleInterpolate schema wrapper

enum(‘rgb’, ‘lab’, ‘hcl’, ‘hsl’, ‘hsl-long’, ‘hcl-long’, ‘cubehelix’, ‘cubehelix-long’)

class altair.ScaleInterpolateParams(type=Undefined, gamma=Undefined, **kwds)

ScaleInterpolateParams schema wrapper

Mapping(required=[type])

Attributes

type (enum(‘rgb’, ‘cubehelix’, ‘cubehelix-long’))
gamma (float)
class altair.ScaleResolveMap(color=Undefined, fill=Undefined, opacity=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, x=Undefined, y=Undefined, **kwds)

ScaleResolveMap schema wrapper

Mapping(required=[])

Attributes

color (ResolveMode)
fill (ResolveMode)
opacity (ResolveMode)
shape (ResolveMode)
size (ResolveMode)
stroke (ResolveMode)
x (ResolveMode)
y (ResolveMode)
class altair.ScaleType(*args)

ScaleType schema wrapper

enum(‘linear’, ‘bin-linear’, ‘log’, ‘pow’, ‘sqrt’, ‘time’, ‘utc’, ‘sequential’, ‘ordinal’, ‘bin-ordinal’, ‘point’, ‘band’)

class altair.SchemaBase(*args, **kwds)

Base class for schema wrappers.

Each derived class should set the _schema class attribute (and optionally the _rootschema class attribute) which is used for validation.

copy(deep=True, ignore=())

Return a copy of the object

Parameters:

deep : boolean, optional

if True (default) then return a deep copy of all dict, list, and SchemaBase objects within the object structure

ignore : list, optional

A list of keys for which the contents should not be copied, but only stored by reference.

classmethod from_dict(dct, validate=True, _wrapper_classes=None)

Construct class from a dictionary representation

Parameters:

dct : dictionary

The dict from which to construct the class

validate : boolean

If True (default), then validate the input against the schema.

_wrapper_classes : list (optional)

The set of SchemaBase classes to use when constructing wrappers of the dict inputs. If not specified, the result of cls._default_wrapper_classes will be used.

Returns:

obj : Schema object

The wrapped schema

Raises:

jsonschema.ValidationError :

if validate=True and dct does not conform to the schema

classmethod from_json(json_string, validate=True, **kwargs)

Instantiate the object from a valid JSON string

Parameters:

json_string : string

The string containing a valid JSON chart specification.

validate : boolean

If True (default), then validate the input against the schema.

**kwargs :

Additional keyword arguments are passed to json.loads

Returns:

chart : Chart object

The altair Chart object built from the specification.

classmethod resolve_references(schema)

Resolve references of the schema the context of this object’s schema

to_dict(validate=True, ignore=[], context={})

Return a dictionary representation of the object

Parameters:

validate : boolean or string

If True (default), then validate the output dictionary against the schema. If “deep” then recursively validate all objects in the spec. This takes much more time, but it results in friendlier tracebacks for large objects.

ignore : list

A list of keys to ignore. This will not passed to child to_dict function calls.

context : dict (optional)

A context dictionary that will be passed to all child to_dict function calls

Returns:

dct : dictionary

The dictionary representation of this object

Raises:

jsonschema.ValidationError :

if validate=True and the dict does not conform to the schema

to_json(validate=True, ignore=[], context={}, indent=2, sort_keys=True, **kwargs)

Emit the JSON representation for this object as a string.

Parameters:

validate : boolean or string

If True (default), then validate the output dictionary against the schema. If “deep” then recursively validate all objects in the spec. This takes much more time, but it results in friendlier tracebacks for large objects.

ignore : list

A list of keys to ignore. This will not passed to child to_dict function calls.

context : dict (optional)

A context dictionary that will be passed to all child to_dict function calls

indent : integer, default 2

the number of spaces of indentation to use

sort_keys : boolean, default True

if True, sort keys in the output

**kwargs

Additional keyword arguments are passed to json.dumps()

Returns:

spec : string

The JSON specification of the chart object.

classmethod validate(instance, schema=None)

Validate the instance against the class schema in the context of the rootschema.

class altair.SchemeParams(name=Undefined, extent=Undefined, **kwds)

SchemeParams schema wrapper

Mapping(required=[name])

Attributes

name (string) A color scheme name for sequential/ordinal scales (e.g., “category10” or “viridis”). For the full list of supported scheme, please refer to the [Vega Scheme](https://vega.github.io/vega/docs/schemes/#reference) reference.
extent (List(float)) For sequential and diverging schemes only, determines the extent of the color range to use. For example [0.2, 1] will rescale the color scheme such that color values in the range _[0, 0.2)_ are excluded from the scheme.
class altair.SelectionAnd(**kwds)

SelectionAnd schema wrapper

Mapping(required=[and])

class altair.SelectionConfig(interval=Undefined, multi=Undefined, single=Undefined, **kwds)

SelectionConfig schema wrapper

Mapping(required=[])

Attributes

interval (IntervalSelectionConfig) The default definition for an [interval](selection.html#type) selection. All properties and transformations for an interval selection definition (except type) may be specified here. For instance, setting interval to {“translate”: false} disables the ability to move interval selections by default.
multi (MultiSelectionConfig) The default definition for a [multi](selection.html#type) selection. All properties and transformations for a multi selection definition (except type) may be specified here. For instance, setting multi to {“toggle”: “event.altKey”} adds additional values to multi selections when clicking with the alt-key pressed by default.
single (SingleSelectionConfig) The default definition for a [single](selection.html#type) selection. All properties and transformations for a single selection definition (except type) may be specified here. For instance, setting single to {“on”: “dblclick”} populates single selections on double-click by default.
class altair.SelectionDef(*args, **kwds)

SelectionDef schema wrapper

anyOf(SingleSelection, MultiSelection, IntervalSelection)

class altair.SelectionDomain(*args, **kwds)

SelectionDomain schema wrapper

anyOf(Mapping(required=[selection]), Mapping(required=[selection]))

class altair.SelectionMapping(*args, **kwds)

A mapping of selection names to selection definitions.

This is designed to match the schema of the “selection” property of top-level objects.

class altair.SelectionNot(**kwds)

SelectionNot schema wrapper

Mapping(required=[not])

class altair.SelectionOperand(*args, **kwds)

SelectionOperand schema wrapper

anyOf(SelectionNot, SelectionAnd, SelectionOr, string)

class altair.SelectionOr(**kwds)

SelectionOr schema wrapper

Mapping(required=[or])

class altair.SelectionPredicate(selection=Undefined, **kwds)

SelectionPredicate schema wrapper

Mapping(required=[selection])

Attributes

selection (SelectionOperand) Filter using a selection name.
class altair.SelectionResolution(*args)

SelectionResolution schema wrapper

enum(‘global’, ‘union’, ‘intersect’)

class altair.Shape(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Shape schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.ShapeValue(value, condition=Undefined, **kwds)

ShapeValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.SingleDefChannel(*args)

SingleDefChannel schema wrapper

enum(‘x’, ‘y’, ‘x2’, ‘y2’, ‘longitude’, ‘latitude’, ‘longitude2’, ‘latitude2’, ‘row’, ‘column’, ‘color’, ‘fill’, ‘stroke’, ‘size’, ‘shape’, ‘opacity’, ‘text’, ‘tooltip’, ‘href’, ‘key’)

class altair.SingleSelection(type=Undefined, bind=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, nearest=Undefined, on=Undefined, resolve=Undefined, **kwds)

SingleSelection schema wrapper

Mapping(required=[type])

Attributes

type (enum(‘single’))
bind (anyOf(VgBinding, Mapping(required=[]))) Establish a two-way binding between a single selection and input elements (also known as dynamic query widgets). A binding takes the form of Vega’s [input element binding definition](https://vega.github.io/vega/docs/signals/#bind) or can be a mapping between projected field/encodings and binding definitions. See the [bind transform](bind.html) documentation for more information.
empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
nearest (boolean) When true, an invisible voronoi diagram is computed to accelerate discrete selection. The data value _nearest_ the mouse cursor is added to the selection. See the [nearest transform](nearest.html) documentation for more information.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
class altair.SingleSelectionConfig(bind=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, nearest=Undefined, on=Undefined, resolve=Undefined, **kwds)

SingleSelectionConfig schema wrapper

Mapping(required=[])

Attributes

bind (anyOf(VgBinding, Mapping(required=[]))) Establish a two-way binding between a single selection and input elements (also known as dynamic query widgets). A binding takes the form of Vega’s [input element binding definition](https://vega.github.io/vega/docs/signals/#bind) or can be a mapping between projected field/encodings and binding definitions. See the [bind transform](bind.html) documentation for more information.
empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
nearest (boolean) When true, an invisible voronoi diagram is computed to accelerate discrete selection. The data value _nearest_ the mouse cursor is added to the selection. See the [nearest transform](nearest.html) documentation for more information.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
class altair.SingleTimeUnit(*args, **kwds)

SingleTimeUnit schema wrapper

anyOf(LocalSingleTimeUnit, UtcSingleTimeUnit)

class altair.Size(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Size schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.SizeValue(value, condition=Undefined, **kwds)

SizeValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.SortField(op=Undefined, field=Undefined, order=Undefined, **kwds)

SortField schema wrapper

Mapping(required=[op])

Attributes

op (AggregateOp) An [aggregate operation](aggregate.html#ops) to perform on the field prior to sorting (e.g., “count”, “mean” and “median”). This property is required in cases where the sort field and the data reference field do not match. The input data objects will be aggregated, grouped by the encoded data field. For a full list of operations, please see the documentation for [aggregate](aggregate.html#ops).
field (anyOf(string, RepeatRef)) The data [field](field.html) to sort by. __Default value:__ If unspecified, defaults to the field specified in the outer data reference.
order (SortOrder) The sort order. One of “ascending” (default) or “descending”.
class altair.SortOrder(*args)

SortOrder schema wrapper

enum(‘ascending’, ‘descending’, None)

class altair.Spec(*args, **kwds)

Spec schema wrapper

anyOf(CompositeUnitSpec, LayerSpec, FacetSpec, RepeatSpec, VConcatSpec, HConcatSpec)

class altair.StackOffset(*args)

StackOffset schema wrapper

enum(‘zero’, ‘center’, ‘normalize’)

class altair.Stroke(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, legend=Undefined, scale=Undefined, sort=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Stroke schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
legend (anyOf(Legend, None)) An object defining properties of the legend. If null, the legend for the encoding channel will be removed. __Default value:__ If undefined, default [legend properties](https://vega.github.io/vega-lite/docs/legend.html) are applied.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.StrokeValue(value, condition=Undefined, **kwds)

StrokeValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalMarkPropFieldDef, ConditionalValueDef,)
List(ConditionalValueDef)) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.StyleConfigIndex(**kwds)

StyleConfigIndex schema wrapper

Mapping(required=[])

class altair.Text(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, format=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Text schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
format (string) The [formatting pattern](https://vega.github.io/vega-lite/docs/format.html) for a text field. If not defined, this will be determined automatically.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.TextConfig(align=Undefined, angle=Undefined, baseline=Undefined, color=Undefined, cursor=Undefined, dx=Undefined, dy=Undefined, fill=Undefined, fillOpacity=Undefined, filled=Undefined, font=Undefined, fontSize=Undefined, fontStyle=Undefined, fontWeight=Undefined, href=Undefined, interpolate=Undefined, limit=Undefined, opacity=Undefined, orient=Undefined, radius=Undefined, shape=Undefined, shortTimeLabels=Undefined, size=Undefined, stroke=Undefined, strokeDash=Undefined, strokeDashOffset=Undefined, strokeOpacity=Undefined, strokeWidth=Undefined, tension=Undefined, text=Undefined, theta=Undefined, **kwds)

TextConfig schema wrapper

Mapping(required=[])

Attributes

align (HorizontalAlign) The horizontal alignment of the text. One of “left”, “right”, “center”.
angle (float) The rotation angle of the text, in degrees.
baseline (VerticalAlign) The vertical alignment of the text. One of “top”, “middle”, “bottom”. __Default value:__ “middle”
color (string) Default color. Note that fill and stroke have higher precedence than color and will override color. __Default value:__ <span style=”color: #4682b4;”>&#9632;</span> “#4682b4” __Note:__ This property cannot be used in a [style config](mark.html#style-config).
cursor (enum(‘auto’, ‘default’, ‘none’, ‘context-menu’, ‘help’, ‘pointer’, ‘progress’,)
‘wait’, ‘cell’, ‘crosshair’, ‘text’, ‘vertical-text’, ‘alias’, ‘copy’, ‘move’, ‘no-drop’,  
‘not-allowed’, ‘e-resize’, ‘n-resize’, ‘ne-resize’, ‘nw-resize’, ‘s-resize’, ‘se-resize’,  
‘sw-resize’, ‘w-resize’, ‘ew-resize’, ‘ns-resize’, ‘nesw-resize’, ‘nwse-resize’,  
‘col-resize’, ‘row-resize’, ‘all-scroll’, ‘zoom-in’, ‘zoom-out’, ‘grab’, ‘grabbing’) The mouse cursor used over the mark. Any valid [CSS cursor type](https://developer.mozilla.org/en-US/docs/Web/CSS/cursor#Values) can be used.
dx (float) The horizontal offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
dy (float) The vertical offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
fill (string) Default Fill Color. This has higher precedence than config.color __Default value:__ (None)
fillOpacity (float) The fill opacity (value between [0,1]). __Default value:__ 1
filled (boolean) Whether the mark’s color should be used as fill color instead of stroke color. __Default value:__ true for all marks except point and false for point. __Applicable for:__ bar, point, circle, square, and area marks. __Note:__ This property cannot be used in a [style config](mark.html#style-config).
font (string) The typeface to set the text in (e.g., “Helvetica Neue”).
fontSize (float) The font size, in pixels.
fontStyle (FontStyle) The font style (e.g., “italic”).
fontWeight (FontWeight) The font weight. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
href (string) A URL to load upon mouse click. If defined, the mark acts as a hyperlink.
interpolate (Interpolate) The line interpolation method to use for line and area marks. One of the following: - “linear”: piecewise linear segments, as in a polyline. - “linear-closed”: close the linear segments to form a polygon. - “step”: alternate between horizontal and vertical segments, as in a step function. - “step-before”: alternate between vertical and horizontal segments, as in a step function. - “step-after”: alternate between horizontal and vertical segments, as in a step function. - “basis”: a B-spline, with control point duplication on the ends. - “basis-open”: an open B-spline; may not intersect the start or end. - “basis-closed”: a closed B-spline, as in a loop. - “cardinal”: a Cardinal spline, with control point duplication on the ends. - “cardinal-open”: an open Cardinal spline; may not intersect the start or end, but will intersect other control points. - “cardinal-closed”: a closed Cardinal spline, as in a loop. - “bundle”: equivalent to basis, except the tension parameter is used to straighten the spline. - “monotone”: cubic interpolation that preserves monotonicity in y.
limit (float) The maximum length of the text mark in pixels (default 0, indicating no limit). The text value will be automatically truncated if the rendered size exceeds the limit.
opacity (float) The overall opacity (value between [0,1]). __Default value:__ 0.7 for non-aggregate plots with point, tick, circle, or square marks or layered bar charts and 1 otherwise.
orient (Orient) The orientation of a non-stacked bar, tick, area, and line charts. The value is either horizontal (default) or vertical. - For bar, rule and tick, this determines whether the size of the bar and tick should be applied to x or y dimension. - For area, this property determines the orient property of the Vega output. - For line, this property determines the sort order of the points in the line if config.sortLineBy is not specified. For stacked charts, this is always determined by the orientation of the stack; therefore explicitly specified value will be ignored.
radius (float) Polar coordinate radial offset, in pixels, of the text label from the origin determined by the x and y properties.
shape (string) The default symbol shape to use. One of: “circle” (default), “square”, “cross”, “diamond”, “triangle-up”, or “triangle-down”, or a custom SVG path. __Default value:__ “circle”
shortTimeLabels (boolean) Whether month names and weekday names should be abbreviated.
size (float) The pixel area each the point/circle/square. For example: in the case of circles, the radius is determined in part by the square root of the size value. __Default value:__ 30
stroke (string) Default Stroke Color. This has higher precedence than config.color __Default value:__ (None)
strokeDash (List(float)) An array of alternating stroke, space lengths for creating dashed or dotted lines.
strokeDashOffset (float) The offset (in pixels) into which to begin drawing with the stroke dash array.
strokeOpacity (float) The stroke opacity (value between [0,1]). __Default value:__ 1
strokeWidth (float) The stroke width, in pixels.
tension (float) Depending on the interpolation type, sets the tension parameter (for line and area marks).
text (string) Placeholder text if the text channel is not specified
theta (float) Polar coordinate angle, in radians, of the text label from the origin determined by the x and y properties. Values for theta follow the same convention of arc mark startAngle and endAngle properties: angles are measured in radians, with 0 indicating “north”.
class altair.TextFieldDefWithCondition(type=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, format=Undefined, timeUnit=Undefined, **kwds)

TextFieldDefWithCondition schema wrapper

Mapping(required=[type]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
format (string) The [formatting pattern](https://vega.github.io/vega-lite/docs/format.html) for a text field. If not defined, this will be determined automatically.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
class altair.TextValue(value, condition=Undefined, **kwds)

TextValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalTextFieldDef, ConditionalValueDef, List(ConditionalValueDef))) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.TextValueDefWithCondition(condition=Undefined, value=Undefined, **kwds)

TextValueDefWithCondition schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalTextFieldDef, ConditionalValueDef, List(ConditionalValueDef))) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.TickConfig(align=Undefined, angle=Undefined, bandSize=Undefined, baseline=Undefined, color=Undefined, cursor=Undefined, dx=Undefined, dy=Undefined, fill=Undefined, fillOpacity=Undefined, filled=Undefined, font=Undefined, fontSize=Undefined, fontStyle=Undefined, fontWeight=Undefined, href=Undefined, interpolate=Undefined, limit=Undefined, opacity=Undefined, orient=Undefined, radius=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, strokeDash=Undefined, strokeDashOffset=Undefined, strokeOpacity=Undefined, strokeWidth=Undefined, tension=Undefined, text=Undefined, theta=Undefined, thickness=Undefined, **kwds)

TickConfig schema wrapper

Mapping(required=[])

Attributes

align (HorizontalAlign) The horizontal alignment of the text. One of “left”, “right”, “center”.
angle (float) The rotation angle of the text, in degrees.
bandSize (float) The width of the ticks. __Default value:__ 2/3 of rangeStep.
baseline (VerticalAlign) The vertical alignment of the text. One of “top”, “middle”, “bottom”. __Default value:__ “middle”
color (string) Default color. Note that fill and stroke have higher precedence than color and will override color. __Default value:__ <span style=”color: #4682b4;”>&#9632;</span> “#4682b4” __Note:__ This property cannot be used in a [style config](mark.html#style-config).
cursor (enum(‘auto’, ‘default’, ‘none’, ‘context-menu’, ‘help’, ‘pointer’, ‘progress’,)
‘wait’, ‘cell’, ‘crosshair’, ‘text’, ‘vertical-text’, ‘alias’, ‘copy’, ‘move’, ‘no-drop’,  
‘not-allowed’, ‘e-resize’, ‘n-resize’, ‘ne-resize’, ‘nw-resize’, ‘s-resize’, ‘se-resize’,  
‘sw-resize’, ‘w-resize’, ‘ew-resize’, ‘ns-resize’, ‘nesw-resize’, ‘nwse-resize’,  
‘col-resize’, ‘row-resize’, ‘all-scroll’, ‘zoom-in’, ‘zoom-out’, ‘grab’, ‘grabbing’) The mouse cursor used over the mark. Any valid [CSS cursor type](https://developer.mozilla.org/en-US/docs/Web/CSS/cursor#Values) can be used.
dx (float) The horizontal offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
dy (float) The vertical offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
fill (string) Default Fill Color. This has higher precedence than config.color __Default value:__ (None)
fillOpacity (float) The fill opacity (value between [0,1]). __Default value:__ 1
filled (boolean) Whether the mark’s color should be used as fill color instead of stroke color. __Default value:__ true for all marks except point and false for point. __Applicable for:__ bar, point, circle, square, and area marks. __Note:__ This property cannot be used in a [style config](mark.html#style-config).
font (string) The typeface to set the text in (e.g., “Helvetica Neue”).
fontSize (float) The font size, in pixels.
fontStyle (FontStyle) The font style (e.g., “italic”).
fontWeight (FontWeight) The font weight. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
href (string) A URL to load upon mouse click. If defined, the mark acts as a hyperlink.
interpolate (Interpolate) The line interpolation method to use for line and area marks. One of the following: - “linear”: piecewise linear segments, as in a polyline. - “linear-closed”: close the linear segments to form a polygon. - “step”: alternate between horizontal and vertical segments, as in a step function. - “step-before”: alternate between vertical and horizontal segments, as in a step function. - “step-after”: alternate between horizontal and vertical segments, as in a step function. - “basis”: a B-spline, with control point duplication on the ends. - “basis-open”: an open B-spline; may not intersect the start or end. - “basis-closed”: a closed B-spline, as in a loop. - “cardinal”: a Cardinal spline, with control point duplication on the ends. - “cardinal-open”: an open Cardinal spline; may not intersect the start or end, but will intersect other control points. - “cardinal-closed”: a closed Cardinal spline, as in a loop. - “bundle”: equivalent to basis, except the tension parameter is used to straighten the spline. - “monotone”: cubic interpolation that preserves monotonicity in y.
limit (float) The maximum length of the text mark in pixels (default 0, indicating no limit). The text value will be automatically truncated if the rendered size exceeds the limit.
opacity (float) The overall opacity (value between [0,1]). __Default value:__ 0.7 for non-aggregate plots with point, tick, circle, or square marks or layered bar charts and 1 otherwise.
orient (Orient) The orientation of a non-stacked bar, tick, area, and line charts. The value is either horizontal (default) or vertical. - For bar, rule and tick, this determines whether the size of the bar and tick should be applied to x or y dimension. - For area, this property determines the orient property of the Vega output. - For line, this property determines the sort order of the points in the line if config.sortLineBy is not specified. For stacked charts, this is always determined by the orientation of the stack; therefore explicitly specified value will be ignored.
radius (float) Polar coordinate radial offset, in pixels, of the text label from the origin determined by the x and y properties.
shape (string) The default symbol shape to use. One of: “circle” (default), “square”, “cross”, “diamond”, “triangle-up”, or “triangle-down”, or a custom SVG path. __Default value:__ “circle”
size (float) The pixel area each the point/circle/square. For example: in the case of circles, the radius is determined in part by the square root of the size value. __Default value:__ 30
stroke (string) Default Stroke Color. This has higher precedence than config.color __Default value:__ (None)
strokeDash (List(float)) An array of alternating stroke, space lengths for creating dashed or dotted lines.
strokeDashOffset (float) The offset (in pixels) into which to begin drawing with the stroke dash array.
strokeOpacity (float) The stroke opacity (value between [0,1]). __Default value:__ 1
strokeWidth (float) The stroke width, in pixels.
tension (float) Depending on the interpolation type, sets the tension parameter (for line and area marks).
text (string) Placeholder text if the text channel is not specified
theta (float) Polar coordinate angle, in radians, of the text label from the origin determined by the x and y properties. Values for theta follow the same convention of arc mark startAngle and endAngle properties: angles are measured in radians, with 0 indicating “north”.
thickness (float) Thickness of the tick mark. __Default value:__ 1
class altair.TimeUnit(*args, **kwds)

TimeUnit schema wrapper

anyOf(SingleTimeUnit, MultiTimeUnit)

class altair.TimeUnitTransform(field=Undefined, timeUnit=Undefined, **kwds)

TimeUnitTransform schema wrapper

Mapping(required=[timeUnit, field, as])

Attributes

field (string) The data field to apply time unit.
timeUnit (TimeUnit) The timeUnit.
class altair.TitleOrient(*args)

TitleOrient schema wrapper

enum(‘top’, ‘bottom’, ‘left’, ‘right’)

class altair.TitleParams(text=Undefined, anchor=Undefined, offset=Undefined, orient=Undefined, style=Undefined, **kwds)

TitleParams schema wrapper

Mapping(required=[text])

Attributes

text (string) The title text.
anchor (Anchor) The anchor position for placing the title. One of “start”, “middle”, or “end”. For example, with an orientation of top these anchor positions map to a left-, center-, or right-aligned title. __Default value:__ “middle” for [single](spec.html) and [layered](layer.html) views. “start” for other composite views. __Note:__ [For now](https://github.com/vega/vega-lite/issues/2875), anchor is only customizable only for [single](spec.html) and [layered](layer.html) views. For other composite views, anchor is always “start”.
offset (float) The orthogonal offset in pixels by which to displace the title from its position along the edge of the chart.
orient (TitleOrient) The orientation of the title relative to the chart. One of “top” (the default), “bottom”, “left”, or “right”.
style (anyOf(string, List(string))) A [mark style property](config.html#style) to apply to the title text mark. __Default value:__ “group-title”.
class altair.Tooltip(shorthand=Undefined, aggregate=Undefined, bin=Undefined, condition=Undefined, field=Undefined, format=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Tooltip schema wrapper

Mapping(required=[shorthand]) A FieldDef with Condition<ValueDef> {

condition: {value: …}, field: …, …

}

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
condition (anyOf(ConditionalValueDef, List(ConditionalValueDef))) One or more value definition(s) with a selection predicate. __Note:__ A field definition’s condition property can only contain [value definitions](https://vega.github.io/vega-lite/docs/encoding.html#value-def) since Vega-Lite only allows at most one encoded field per encoding channel.
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
format (string) The [formatting pattern](https://vega.github.io/vega-lite/docs/format.html) for a text field. If not defined, this will be determined automatically.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.TooltipValue(value, condition=Undefined, **kwds)

TooltipValue schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalTextFieldDef, ConditionalValueDef, List(ConditionalValueDef))) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.TopLevelFacetSpec(data=Undefined, facet=Undefined, spec=Undefined, autosize=Undefined, background=Undefined, config=Undefined, datasets=Undefined, description=Undefined, name=Undefined, padding=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, **kwds)

TopLevelFacetSpec schema wrapper

Mapping(required=[data, facet, spec])

Attributes

data (Data) An object describing the data source
facet (FacetMapping) An object that describes mappings between row and column channels and their field definitions.
spec (anyOf(LayerSpec, CompositeUnitSpec)) A specification of the view that gets faceted.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale, axis, and legend resolutions for facets.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.TopLevelFacetedUnitSpec(data=Undefined, mark=Undefined, autosize=Undefined, background=Undefined, config=Undefined, datasets=Undefined, description=Undefined, encoding=Undefined, height=Undefined, name=Undefined, padding=Undefined, projection=Undefined, selection=Undefined, title=Undefined, transform=Undefined, width=Undefined, **kwds)

TopLevelFacetedUnitSpec schema wrapper

Mapping(required=[data, mark])

Attributes

data (Data) An object describing the data source
mark (AnyMark) A string describing the mark type (one of “bar”, “circle”, “square”, “tick”, “line”, * “area”, “point”, “rule”, “geoshape”, and “text”) or a [mark definition object](https://vega.github.io/vega-lite/docs/mark.html#mark-def).
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
encoding (EncodingWithFacet) A key-value mapping between encoding channels and definition of fields.
height (float) The height of a visualization. __Default value:__ - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its y-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - For y-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the height is [determined by the range step, paddings, and the cardinality of the field mapped to y-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to y channel, the height will be the value of rangeStep. __Note__: For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the height of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
projection (Projection) An object defining properties of geographic projection. Works with “geoshape” marks and “point” or “line” marks that have latitude and “longitude” channels.
selection (Mapping(required=[])) A key-value mapping between selection names and definitions.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
width (float) The width of a visualization. __Default value:__ This will be determined by the following rules: - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its x-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - For x-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the width is [determined by the range step, paddings, and the cardinality of the field mapped to x-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to x channel, the width will be the value of [config.scale.textXRangeStep](https://vega.github.io/vega-lite/docs/size.html#default-width-and-height) for text mark and the value of rangeStep for other marks. __Note:__ For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the width of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
class altair.TopLevelHConcatSpec(hconcat=Undefined, autosize=Undefined, background=Undefined, config=Undefined, data=Undefined, datasets=Undefined, description=Undefined, name=Undefined, padding=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, **kwds)

TopLevelHConcatSpec schema wrapper

Mapping(required=[hconcat])

Attributes

hconcat (List(Spec)) A list of views that should be concatenated and put into a row.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale, axis, and legend resolutions for horizontally concatenated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.TopLevelLayerSpec(layer=Undefined, autosize=Undefined, background=Undefined, config=Undefined, data=Undefined, datasets=Undefined, description=Undefined, encoding=Undefined, height=Undefined, name=Undefined, padding=Undefined, projection=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, width=Undefined, **kwds)

TopLevelLayerSpec schema wrapper

Mapping(required=[layer])

Attributes

layer (List(anyOf(LayerSpec, CompositeUnitSpec))) Layer or single view specifications to be layered. __Note__: Specifications inside layer cannot use row and column channels as layering facet specifications is not allowed.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
encoding (Encoding) A shared key-value mapping between encoding channels and definition of fields in the underlying layers.
height (float) The height of a visualization. __Default value:__ - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its y-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - For y-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the height is [determined by the range step, paddings, and the cardinality of the field mapped to y-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the height will be the value of [config.view.height](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to y channel, the height will be the value of rangeStep. __Note__: For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the height of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
projection (Projection) An object defining properties of the geographic projection shared by underlying layers.
resolve (Resolve) Scale, axis, and legend resolutions for layers.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
width (float) The width of a visualization. __Default value:__ This will be determined by the following rules: - If a view’s [autosize](https://vega.github.io/vega-lite/docs/size.html#autosize) type is “fit” or its x-channel has a [continuous scale](https://vega.github.io/vega-lite/docs/scale.html#continuous), the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - For x-axis with a band or point scale: if [rangeStep](https://vega.github.io/vega-lite/docs/scale.html#band) is a numeric value or unspecified, the width is [determined by the range step, paddings, and the cardinality of the field mapped to x-channel](https://vega.github.io/vega-lite/docs/scale.html#band). Otherwise, if the rangeStep is null, the width will be the value of [config.view.width](https://vega.github.io/vega-lite/docs/spec.html#config). - If no field is mapped to x channel, the width will be the value of [config.scale.textXRangeStep](https://vega.github.io/vega-lite/docs/size.html#default-width-and-height) for text mark and the value of rangeStep for other marks. __Note:__ For plots with [row and column channels](https://vega.github.io/vega-lite/docs/encoding.html#facet), this represents the width of a single view. __See also:__ The documentation for [width and height](https://vega.github.io/vega-lite/docs/size.html) contains more examples.
class altair.TopLevelMixin

Mixin for top-level chart objects such as Chart, LayeredChart, etc.

properties(**kwargs)

Set top-level properties of the Chart.

Argument names and types are the same as class initialization.

repeat(row=Undefined, column=Undefined, **kwargs)

Return a RepeatChart built from the chart

Fields within the chart can be set to correspond to the row or column using alt.repeat(‘row’) and alt.repeat(‘column’).

Parameters:

row : list

a list of data column names to be mapped to the row facet

column : list

a list of data column names to be mapped to the column facet

Returns:

chart : RepeatChart

a repeated chart.

resolve_axis(x=Undefined, y=Undefined, **kwds)

AxisResolveMap schema wrapper

Mapping(required=[])

Attributes

x (ResolveMode)
y (ResolveMode)
resolve_legend(color=Undefined, fill=Undefined, opacity=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, **kwds)

LegendResolveMap schema wrapper

Mapping(required=[])

Attributes

color (ResolveMode)
fill (ResolveMode)
opacity (ResolveMode)
shape (ResolveMode)
size (ResolveMode)
stroke (ResolveMode)
resolve_scale(color=Undefined, fill=Undefined, opacity=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, x=Undefined, y=Undefined, **kwds)

ScaleResolveMap schema wrapper

Mapping(required=[])

Attributes

color (ResolveMode)
fill (ResolveMode)
opacity (ResolveMode)
shape (ResolveMode)
size (ResolveMode)
stroke (ResolveMode)
x (ResolveMode)
y (ResolveMode)
save(fp, format=None, **kwargs)

Save a chart to file in a variety of formats

Supported formats are json, html, png, svg

Parameters:

fp : string filename or file-like object

file in which to write the chart.

format : string (optional)

the format to write: one of [‘json’, ‘html’, ‘png’, ‘svg’]. If not specified, the format will be determined from the filename.

**kwargs :

Additional keyword arguments are passed to the output method associated with the specified format.

savechart(fp, format=None, **kwargs)

Save a chart to file in a variety of formats

Supported formats are json, html, png, svg

Parameters:

fp : string filename or file-like object

file in which to write the chart.

format : string (optional)

the format to write: one of [‘json’, ‘html’, ‘png’, ‘svg’]. If not specified, the format will be determined from the filename.

**kwargs :

Additional keyword arguments are passed to the output method associated with the specified format.

to_dict(*args, **kwargs)

Convert the chart to a dictionary suitable for JSON export

transform_aggregate(aggregate=Undefined, groupby=Undefined, **kwds)

Add an AggregateTransform to the schema.

Parameters:

aggregate : List(AggregatedFieldDef)

Array of objects that define fields to aggregate.

groupby : List(string)

The data fields to group by. If not specified, a single group containing all data objects will be used.

**kwds :

additional keywords are converted to aggregates using standard shorthand parsing.

Returns:

self : Chart object

returns chart to allow for chaining

See also

alt.AggregateTransform
underlying transform object

Examples

The aggregate transform allows you to specify transforms directly using the same shorthand syntax as used in encodings:

>>> import altair as alt
>>> chart1 = alt.Chart().transform_aggregate(
...     mean_acc='mean(Acceleration)',
...     groupby=['Origin']
... )
>>> print(chart1.transform[0].to_json())  
{
  "aggregate": [
    {
      "as": "mean_acc",
      "field": "Acceleration",
      "op": "mean"
    }
  ],
  "groupby": [
    "Origin"
  ]
}

It also supports including AggregatedFieldDef instances or dicts directly, so you can create the above transform like this:

>>> chart2 = alt.Chart().transform_aggregate(
...     [alt.AggregatedFieldDef(field='Acceleration', op='mean',
...                             **{'as': 'mean_acc'})],
...     groupby=['Origin']
... )
>>> chart2.transform == chart1.transform
True
transform_bin(as_=Undefined, field=Undefined, bin=True, **kwargs)

Add a BinTransform to the schema.

Returns:

self : Chart object

returns chart to allow for chaining

See also

alt.BinTransform
underlying transform object

Examples

>>> import altair as alt
>>> chart = alt.Chart().transform_bin("x_binned", "x")
>>> chart.transform[0]
BinTransform({
  as: 'x_binned',
  bin: True,
  field: 'x'
})
>>> chart = alt.Chart().transform_bin("x_binned", "x",
...                                   bin=alt.Bin(maxbins=10))
>>> chart.transform[0]
BinTransform({
  as: 'x_binned',
  bin: BinParams({
    maxbins: 10
  }),
  field: 'x'
})

Attributes

as_ (string) The output fields at which to write the start and end bin values.
bin (anyOf(boolean, BinParams)) An object indicating bin properties, or simply true for using default bin parameters.
field (string) The data field to bin.
transform_calculate(as_=Undefined, calculate=Undefined, **kwargs)

Add a CalculateTransform to the schema.

Returns:

self : Chart object

returns chart to allow for chaining

See also

alt.CalculateTransform
underlying transform object

Examples

>>> import altair as alt
>>> from altair import datum, expr
>>> chart = alt.Chart().transform_calculate(y = 2 * expr.sin(datum.x))
>>> chart.transform[0]
CalculateTransform({
  as: 'y',
  calculate: (2 * sin(datum.x))
})

It’s also possible to pass the CalculateTransform arguments directly:

>>> kwds = {'as': 'y', 'calculate': '2 * sin(datum.x)'}
>>> chart = alt.Chart().transform_calculate(**kwds)
>>> chart.transform[0]
CalculateTransform({
  as: 'y',
  calculate: '2 * sin(datum.x)'
})

As the first form is easier to write and understand, that is the recommended method.

Attributes

as_ (string) The output fields at which to write the start and end bin values.
calculate (string or alt.expr expression) An expression string. Use the variable datum to refer to the current data object.
**kwargs transforms can also be passed by keyword argument; see Examples
transform_filter(filter, **kwargs)

Add a FilterTransform to the schema.

Returns:

self : Chart object

returns chart to allow for chaining

See also

alt.FilterTransform
underlying transform object

Attributes

filter (a filter expression) The filter property must be one of the predicate definitions: (1) a string or alt.expr expression (2) a range predicate (3) a selection predicate (4) a logical operand combining (1)-(3) (5) a NamedSelection object
transform_lookup(as_=Undefined, from_=Undefined, lookup=Undefined, default=Undefined, **kwargs)

Add a LookupTransform to the schema

Returns:

self : Chart object

returns chart to allow for chaining

See also

alt.LookupTransform
underlying transform object

Attributes

as_ (string or List(string)) The field or fields for storing the computed formula value. If from.fields is specified, the transform will use the same names for as. If from.fields is not specified, as has to be a string and we put the whole object into the data under the specified name.
from_ (LookupData) Secondary data reference.
lookup (string) Key in primary data source.
default (string) The default value to use if lookup fails
transform_timeunit(as_=Undefined, field=Undefined, timeUnit=Undefined, **kwargs)

Add a TimeUnitTransform to the schema.

Returns:

self : Chart object

returns chart to allow for chaining

See also

alt.TimeUnitTransform
underlying transform object

Attributes

as_ (string) The output fields at which to write the start and end bin values.
field (string) The data field to apply time unit.
timeUnit (TimeUnit) The timeUnit.
class altair.TopLevelRepeatSpec(repeat=Undefined, spec=Undefined, autosize=Undefined, background=Undefined, config=Undefined, data=Undefined, datasets=Undefined, description=Undefined, name=Undefined, padding=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, **kwds)

TopLevelRepeatSpec schema wrapper

Mapping(required=[repeat, spec])

Attributes

repeat (Repeat) An object that describes what fields should be repeated into views that are laid out as a row or column.
spec (Spec)
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale and legend resolutions for repeated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.TopLevelVConcatSpec(vconcat=Undefined, autosize=Undefined, background=Undefined, config=Undefined, data=Undefined, datasets=Undefined, description=Undefined, name=Undefined, padding=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, **kwds)

TopLevelVConcatSpec schema wrapper

Mapping(required=[vconcat])

Attributes

vconcat (List(Spec)) A list of views that should be concatenated and put into a column.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale, axis, and legend resolutions for vertically concatenated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.TopoDataFormat(feature=Undefined, mesh=Undefined, parse=Undefined, type=Undefined, **kwds)

TopoDataFormat schema wrapper

Mapping(required=[])

Attributes

feature (string) The name of the TopoJSON object set to convert to a GeoJSON feature collection. For example, in a map of the world, there may be an object set named “countries”. Using the feature property, we can extract this set and generate a GeoJSON feature object for each country.
mesh (string) The name of the TopoJSON object set to convert to mesh. Similar to the feature option, mesh extracts a named TopoJSON object set. Unlike the feature option, the corresponding geo data is returned as a single, unified mesh instance, not as individual GeoJSON features. Extracting a mesh is useful for more efficiently drawing borders or other geographic elements that you do not need to associate with specific regions such as individual countries, states or counties.
parse (anyOf(enum(‘auto’), Mapping(required=[]))) If set to auto (the default), perform automatic type inference to determine the desired data types. Alternatively, a parsing directive object can be provided for explicit data types. Each property of the object corresponds to a field name, and the value to the desired data type (one of “number”, “boolean” or “date”). For example, “parse”: {“modified_on”: “date”} parses the modified_on field in each input record a Date value. For “date”, we parse data based using Javascript’s [Date.parse()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/parse). For Specific date formats can be provided (e.g., {foo: ‘date:”%m%d%Y”’}), using the [d3-time-format syntax](https://github.com/d3/d3-time-format#locale_format). UTC date format parsing is supported similarly (e.g., {foo: ‘utc:”%m%d%Y”’}). See more about [UTC time](timeunit.html#utc)
type (enum(‘topojson’)) Type of input data: “json”, “csv”, “tsv”. The default format type is determined by the extension of the file URL. If no extension is detected, “json” will be used by default.
class altair.Transform(*args, **kwds)

Transform schema wrapper

anyOf(FilterTransform, CalculateTransform, LookupTransform, BinTransform, TimeUnitTransform,
AggregateTransform)
class altair.Type(*args, **kwds)

Type schema wrapper

anyOf(BasicType, GeoType) Constants and utilities for data type

Data type based on level of measurement
class altair.UrlData(url=Undefined, format=Undefined, **kwds)

UrlData schema wrapper

Mapping(required=[url])

Attributes

url (string) An URL from which to load the data set. Use the format.type property to ensure the loaded data is correctly parsed.
format (DataFormat) An object that specifies the format for parsing the data file.
class altair.UtcMultiTimeUnit(*args)

UtcMultiTimeUnit schema wrapper

enum(‘utcyearquarter’, ‘utcyearquartermonth’, ‘utcyearmonth’, ‘utcyearmonthdate’, ‘utcyearmonthdatehours’, ‘utcyearmonthdatehoursminutes’, ‘utcyearmonthdatehoursminutesseconds’, ‘utcquartermonth’, ‘utcmonthdate’, ‘utchoursminutes’,

‘utchoursminutesseconds’, ‘utcminutesseconds’, ‘utcsecondsmilliseconds’)
class altair.UtcSingleTimeUnit(*args)

UtcSingleTimeUnit schema wrapper

enum(‘utcyear’, ‘utcquarter’, ‘utcmonth’, ‘utcday’, ‘utcdate’, ‘utchours’, ‘utcminutes’, ‘utcseconds’, ‘utcmilliseconds’)

class altair.VConcatChart(vconcat=(), **kwargs)

A chart with vertically-concatenated facets Mapping(required=[vconcat])

Attributes

vconcat (List(Spec)) A list of views that should be concatenated and put into a column.
autosize (anyOf(AutosizeType, AutoSizeParams)) Sets how the visualization size should be determined. If a string, should be one of “pad”, “fit” or “none”. Object values can additionally specify parameters for content sizing and automatic resizing. “fit” is only supported for single and layered views that don’t use rangeStep. __Default value__: pad
background (string) CSS color property to use as the background of visualization. __Default value:__ none (transparent)
config (Config) Vega-Lite configuration object. This property can only be defined at the top-level of a specification.
data (Data) An object describing the data source
datasets (Datasets) A global data store for named datasets. This is a mapping from names to inline datasets. This can be an array of objects or primitive values or a string. Arrays of primitive values are ingested as objects with a data property.
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
padding (Padding) The default visualization padding, in pixels, from the edge of the visualization canvas to the data rectangle. If a number, specifies padding for all sides. If an object, the value should have the format {“left”: 5, “top”: 5, “right”: 5, “bottom”: 5} to specify padding for each side of the visualization. __Default value__: 5
resolve (Resolve) Scale, axis, and legend resolutions for vertically concatenated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.VConcatSpec(vconcat=Undefined, data=Undefined, description=Undefined, name=Undefined, resolve=Undefined, title=Undefined, transform=Undefined, **kwds)

VConcatSpec schema wrapper

Mapping(required=[vconcat])

Attributes

vconcat (List(Spec)) A list of views that should be concatenated and put into a column.
data (Data) An object describing the data source
description (string) Description of this mark for commenting purpose.
name (string) Name of the visualization for later reference.
resolve (Resolve) Scale, axis, and legend resolutions for vertically concatenated charts.
title (anyOf(string, TitleParams)) Title for the plot.
transform (List(Transform)) An array of data transformations such as filter and new field calculation.
class altair.ValueDef(value=Undefined, **kwds)

ValueDef schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.ValueDefWithCondition(condition=Undefined, value=Undefined, **kwds)

ValueDefWithCondition schema wrapper

Mapping(required=[]) A ValueDef with Condition<ValueDef | FieldDef> {

condition: {field: …} | {value: …}, value: …,

}

Attributes

condition (anyOf(ConditionalFieldDef, ConditionalValueDef, List(ConditionalValueDef))) A field definition or one or more value definition(s) with a selection predicate.
value (anyOf(float, string, boolean)) A constant value in visual domain.
class altair.VegaLite(spec, validate=False)

An IPython/Jupyter display class for rendering VegaLite 2.

class altair.VerticalAlign(*args)

VerticalAlign schema wrapper

enum(‘top’, ‘middle’, ‘bottom’)

class altair.VgAxisConfig(bandPosition=Undefined, domain=Undefined, domainColor=Undefined, domainWidth=Undefined, grid=Undefined, gridColor=Undefined, gridDash=Undefined, gridOpacity=Undefined, gridWidth=Undefined, labelAngle=Undefined, labelBound=Undefined, labelColor=Undefined, labelFlush=Undefined, labelFont=Undefined, labelFontSize=Undefined, labelLimit=Undefined, labelOverlap=Undefined, labelPadding=Undefined, labels=Undefined, maxExtent=Undefined, minExtent=Undefined, tickColor=Undefined, tickRound=Undefined, tickSize=Undefined, tickWidth=Undefined, ticks=Undefined, titleAlign=Undefined, titleAngle=Undefined, titleBaseline=Undefined, titleColor=Undefined, titleFont=Undefined, titleFontSize=Undefined, titleFontWeight=Undefined, titleLimit=Undefined, titleMaxLength=Undefined, titlePadding=Undefined, titleX=Undefined, titleY=Undefined, **kwds)

VgAxisConfig schema wrapper

Mapping(required=[])

Attributes

bandPosition (float) An interpolation fraction indicating where, for band scales, axis ticks should be positioned. A value of 0 places ticks at the left edge of their bands. A value of 0.5 places ticks in the middle of their bands.
domain (boolean) A boolean flag indicating if the domain (the axis baseline) should be included as part of the axis. __Default value:__ true
domainColor (string) Color of axis domain line. __Default value:__ (none, using Vega default).
domainWidth (float) Stroke width of axis domain line __Default value:__ (none, using Vega default).
grid (boolean) A boolean flag indicating if grid lines should be included as part of the axis __Default value:__ true for [continuous scales](scale.html#continuous) that are not binned; otherwise, false.
gridColor (string) Color of gridlines.
gridDash (List(float)) The offset (in pixels) into which to begin drawing with the grid dash array.
gridOpacity (float) The stroke opacity of grid (value between [0,1]) __Default value:__ (1 by default)
gridWidth (float) The grid width, in pixels.
labelAngle (float) The rotation angle of the axis labels. __Default value:__ -90 for nominal and ordinal fields; 0 otherwise.
labelBound (anyOf(boolean, float)) Indicates if labels should be hidden if they exceed the axis range. If false `(the default) no bounds overlap analysis is performed. If `true, labels will be hidden if they exceed the axis range by more than 1 pixel. If this property is a number, it specifies the pixel tolerance: the maximum amount by which a label bounding box may exceed the axis range. __Default value:__ false.
labelColor (string) The color of the tick label, can be in hex color code or regular color name.
labelFlush (anyOf(boolean, float)) Indicates if the first and last axis labels should be aligned flush with the scale range. Flush alignment for a horizontal axis will left-align the first label and right-align the last label. For vertical axes, bottom and top text baselines are applied instead. If this property is a number, it also indicates the number of pixels by which to offset the first and last labels; for example, a value of 2 will flush-align the first and last labels and also push them 2 pixels outward from the center of the axis. The additional adjustment can sometimes help the labels better visually group with corresponding axis ticks. __Default value:__ true for axis of a continuous x-scale. Otherwise, false.
labelFont (string) The font of the tick label.
labelFontSize (float) The font size of the label, in pixels.
labelLimit (float) Maximum allowed pixel width of axis tick labels.
labelOverlap (anyOf(boolean, enum(‘parity’), enum(‘greedy’))) The strategy to use for resolving overlap of axis labels. If false (the default), no overlap reduction is attempted. If set to true or “parity”, a strategy of removing every other label is used (this works well for standard linear axes). If set to “greedy”, a linear scan of the labels is performed, removing any labels that overlaps with the last visible label (this often works better for log-scaled axes). __Default value:__ true for non-nominal fields with non-log scales; “greedy” for log scales; otherwise false.
labelPadding (float) The padding, in pixels, between axis and text labels.
labels (boolean) A boolean flag indicating if labels should be included as part of the axis. __Default value:__ true.
maxExtent (float) The maximum extent in pixels that axis ticks and labels should use. This determines a maximum offset value for axis titles. __Default value:__ undefined.
minExtent (float) The minimum extent in pixels that axis ticks and labels should use. This determines a minimum offset value for axis titles. __Default value:__ 30 for y-axis; undefined for x-axis.
tickColor (string) The color of the axis’s tick.
tickRound (boolean) Boolean flag indicating if pixel position values should be rounded to the nearest integer.
tickSize (float) The size in pixels of axis ticks.
tickWidth (float) The width, in pixels, of ticks.
ticks (boolean) Boolean value that determines whether the axis should include ticks.
titleAlign (string) Horizontal text alignment of axis titles.
titleAngle (float) Angle in degrees of axis titles.
titleBaseline (string) Vertical text baseline for axis titles.
titleColor (string) Color of the title, can be in hex color code or regular color name.
titleFont (string) Font of the title. (e.g., “Helvetica Neue”).
titleFontSize (float) Font size of the title.
titleFontWeight (FontWeight) Font weight of the title. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
titleLimit (float) Maximum allowed pixel width of axis titles.
titleMaxLength (float) Max length for axis title if the title is automatically generated from the field’s description.
titlePadding (float) The padding, in pixels, between title and axis.
titleX (float) X-coordinate of the axis title relative to the axis group.
titleY (float) Y-coordinate of the axis title relative to the axis group.
class altair.VgBinding(*args, **kwds)

VgBinding schema wrapper

anyOf(VgCheckboxBinding, VgRadioBinding, VgSelectBinding, VgRangeBinding, VgGenericBinding)

class altair.VgCheckboxBinding(input=Undefined, element=Undefined, **kwds)

VgCheckboxBinding schema wrapper

Mapping(required=[input])

Attributes

input (enum(‘checkbox’))
element (string)
class altair.VgEventStream(**kwds)

VgEventStream schema wrapper

Mapping(required=[])

class altair.VgGenericBinding(input=Undefined, element=Undefined, **kwds)

VgGenericBinding schema wrapper

Mapping(required=[input])

Attributes

input (string)
element (string)
class altair.VgMarkConfig(align=Undefined, angle=Undefined, baseline=Undefined, cursor=Undefined, dx=Undefined, dy=Undefined, fill=Undefined, fillOpacity=Undefined, font=Undefined, fontSize=Undefined, fontStyle=Undefined, fontWeight=Undefined, href=Undefined, interpolate=Undefined, limit=Undefined, opacity=Undefined, orient=Undefined, radius=Undefined, shape=Undefined, size=Undefined, stroke=Undefined, strokeDash=Undefined, strokeDashOffset=Undefined, strokeOpacity=Undefined, strokeWidth=Undefined, tension=Undefined, text=Undefined, theta=Undefined, **kwds)

VgMarkConfig schema wrapper

Mapping(required=[])

Attributes

align (HorizontalAlign) The horizontal alignment of the text. One of “left”, “right”, “center”.
angle (float) The rotation angle of the text, in degrees.
baseline (VerticalAlign) The vertical alignment of the text. One of “top”, “middle”, “bottom”. __Default value:__ “middle”
cursor (enum(‘auto’, ‘default’, ‘none’, ‘context-menu’, ‘help’, ‘pointer’, ‘progress’,)
‘wait’, ‘cell’, ‘crosshair’, ‘text’, ‘vertical-text’, ‘alias’, ‘copy’, ‘move’, ‘no-drop’,  
‘not-allowed’, ‘e-resize’, ‘n-resize’, ‘ne-resize’, ‘nw-resize’, ‘s-resize’, ‘se-resize’,  
‘sw-resize’, ‘w-resize’, ‘ew-resize’, ‘ns-resize’, ‘nesw-resize’, ‘nwse-resize’,  
‘col-resize’, ‘row-resize’, ‘all-scroll’, ‘zoom-in’, ‘zoom-out’, ‘grab’, ‘grabbing’) The mouse cursor used over the mark. Any valid [CSS cursor type](https://developer.mozilla.org/en-US/docs/Web/CSS/cursor#Values) can be used.
dx (float) The horizontal offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
dy (float) The vertical offset, in pixels, between the text label and its anchor point. The offset is applied after rotation by the _angle_ property.
fill (string) Default Fill Color. This has higher precedence than config.color __Default value:__ (None)
fillOpacity (float) The fill opacity (value between [0,1]). __Default value:__ 1
font (string) The typeface to set the text in (e.g., “Helvetica Neue”).
fontSize (float) The font size, in pixels.
fontStyle (FontStyle) The font style (e.g., “italic”).
fontWeight (FontWeight) The font weight. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
href (string) A URL to load upon mouse click. If defined, the mark acts as a hyperlink.
interpolate (Interpolate) The line interpolation method to use for line and area marks. One of the following: - “linear”: piecewise linear segments, as in a polyline. - “linear-closed”: close the linear segments to form a polygon. - “step”: alternate between horizontal and vertical segments, as in a step function. - “step-before”: alternate between vertical and horizontal segments, as in a step function. - “step-after”: alternate between horizontal and vertical segments, as in a step function. - “basis”: a B-spline, with control point duplication on the ends. - “basis-open”: an open B-spline; may not intersect the start or end. - “basis-closed”: a closed B-spline, as in a loop. - “cardinal”: a Cardinal spline, with control point duplication on the ends. - “cardinal-open”: an open Cardinal spline; may not intersect the start or end, but will intersect other control points. - “cardinal-closed”: a closed Cardinal spline, as in a loop. - “bundle”: equivalent to basis, except the tension parameter is used to straighten the spline. - “monotone”: cubic interpolation that preserves monotonicity in y.
limit (float) The maximum length of the text mark in pixels (default 0, indicating no limit). The text value will be automatically truncated if the rendered size exceeds the limit.
opacity (float) The overall opacity (value between [0,1]). __Default value:__ 0.7 for non-aggregate plots with point, tick, circle, or square marks or layered bar charts and 1 otherwise.
orient (Orient) The orientation of a non-stacked bar, tick, area, and line charts. The value is either horizontal (default) or vertical. - For bar, rule and tick, this determines whether the size of the bar and tick should be applied to x or y dimension. - For area, this property determines the orient property of the Vega output. - For line, this property determines the sort order of the points in the line if config.sortLineBy is not specified. For stacked charts, this is always determined by the orientation of the stack; therefore explicitly specified value will be ignored.
radius (float) Polar coordinate radial offset, in pixels, of the text label from the origin determined by the x and y properties.
shape (string) The default symbol shape to use. One of: “circle” (default), “square”, “cross”, “diamond”, “triangle-up”, or “triangle-down”, or a custom SVG path. __Default value:__ “circle”
size (float) The pixel area each the point/circle/square. For example: in the case of circles, the radius is determined in part by the square root of the size value. __Default value:__ 30
stroke (string) Default Stroke Color. This has higher precedence than config.color __Default value:__ (None)
strokeDash (List(float)) An array of alternating stroke, space lengths for creating dashed or dotted lines.
strokeDashOffset (float) The offset (in pixels) into which to begin drawing with the stroke dash array.
strokeOpacity (float) The stroke opacity (value between [0,1]). __Default value:__ 1
strokeWidth (float) The stroke width, in pixels.
tension (float) Depending on the interpolation type, sets the tension parameter (for line and area marks).
text (string) Placeholder text if the text channel is not specified
theta (float) Polar coordinate angle, in radians, of the text label from the origin determined by the x and y properties. Values for theta follow the same convention of arc mark startAngle and endAngle properties: angles are measured in radians, with 0 indicating “north”.
class altair.VgProjectionType(*args)

VgProjectionType schema wrapper

enum(‘albers’, ‘albersUsa’, ‘azimuthalEqualArea’, ‘azimuthalEquidistant’, ‘conicConformal’, ‘conicEqualArea’, ‘conicEquidistant’, ‘equirectangular’, ‘gnomonic’, ‘mercator’, ‘orthographic’, ‘stereographic’, ‘transverseMercator’)

class altair.VgRadioBinding(input=Undefined, options=Undefined, element=Undefined, **kwds)

VgRadioBinding schema wrapper

Mapping(required=[input, options])

Attributes

input (enum(‘radio’))
options (List(string))
element (string)
class altair.VgRangeBinding(input=Undefined, element=Undefined, max=Undefined, min=Undefined, step=Undefined, **kwds)

VgRangeBinding schema wrapper

Mapping(required=[input])

Attributes

input (enum(‘range’))
element (string)
max (float)
min (float)
step (float)
class altair.VgScheme(scheme=Undefined, count=Undefined, extent=Undefined, **kwds)

VgScheme schema wrapper

Mapping(required=[scheme])

Attributes

scheme (string)
count (float)
extent (List(float))
class altair.VgSelectBinding(input=Undefined, options=Undefined, element=Undefined, **kwds)

VgSelectBinding schema wrapper

Mapping(required=[input, options])

Attributes

input (enum(‘select’))
options (List(string))
element (string)
class altair.VgTitleConfig(anchor=Undefined, angle=Undefined, baseline=Undefined, color=Undefined, font=Undefined, fontSize=Undefined, fontWeight=Undefined, limit=Undefined, offset=Undefined, orient=Undefined, **kwds)

VgTitleConfig schema wrapper

Mapping(required=[])

Attributes

anchor (Anchor) The anchor position for placing the title. One of “start”, “middle”, or “end”. For example, with an orientation of top these anchor positions map to a left-, center-, or right-aligned title. __Default value:__ “middle” for [single](spec.html) and [layered](layer.html) views. “start” for other composite views. __Note:__ [For now](https://github.com/vega/vega-lite/issues/2875), anchor is only customizable only for [single](spec.html) and [layered](layer.html) views. For other composite views, anchor is always “start”.
angle (float) Angle in degrees of title text.
baseline (VerticalAlign) Vertical text baseline for title text.
color (string) Text color for title text.
font (string) Font name for title text.
fontSize (float) Font size in pixels for title text. __Default value:__ 10.
fontWeight (FontWeight) Font weight for title text. This can be either a string (e.g “bold”, “normal”) or a number (100, 200, 300, …, 900 where “normal” = 400 and “bold” = 700).
limit (float) The maximum allowed length in pixels of legend labels.
offset (float) Offset in pixels of the title from the chart body and axes.
orient (TitleOrient) Default title orientation (“top”, “bottom”, “left”, or “right”)
class altair.ViewConfig(clip=Undefined, fill=Undefined, fillOpacity=Undefined, height=Undefined, stroke=Undefined, strokeDash=Undefined, strokeDashOffset=Undefined, strokeOpacity=Undefined, strokeWidth=Undefined, width=Undefined, **kwds)

ViewConfig schema wrapper

Mapping(required=[])

Attributes

clip (boolean) Whether the view should be clipped.
fill (string) The fill color. __Default value:__ (none)
fillOpacity (float) The fill opacity (value between [0,1]). __Default value:__ (none)
height (float) The default height of the single plot or each plot in a trellis plot when the visualization has a continuous (non-ordinal) y-scale with rangeStep = null. __Default value:__ 200
stroke (string) The stroke color. __Default value:__ (none)
strokeDash (List(float)) An array of alternating stroke, space lengths for creating dashed or dotted lines. __Default value:__ (none)
strokeDashOffset (float) The offset (in pixels) into which to begin drawing with the stroke dash array. __Default value:__ (none)
strokeOpacity (float) The stroke opacity (value between [0,1]). __Default value:__ (none)
strokeWidth (float) The stroke width, in pixels. __Default value:__ (none)
width (float) The default width of the single plot or each plot in a trellis plot when the visualization has a continuous (non-ordinal) x-scale or ordinal x-scale with rangeStep = null. __Default value:__ 200
class altair.X(shorthand=Undefined, aggregate=Undefined, axis=Undefined, bin=Undefined, field=Undefined, scale=Undefined, sort=Undefined, stack=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

X schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
axis (anyOf(Axis, None)) An object defining properties of axis’s gridlines, ticks and labels. If null, the axis for the encoding channel will be removed. __Default value:__ If undefined, default [axis properties](https://vega.github.io/vega-lite/docs/axis.html) are applied.
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
stack (anyOf(StackOffset, None)) Type of stacking offset if the field should be stacked. stack is only applicable for x and y channels with continuous domains. For example, stack of y can be used to customize stacking for a vertical bar chart. stack can be one of the following values: - “zero”: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart). - “normalize” - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/> -“center” - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)). - null - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart. __Default value:__ zero for plots with all of the following conditions are true: (1) the mark is bar or area; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, null by default.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.X2(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

X2 schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.X2Value(value, **kwds)

X2Value schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.XValue(value, **kwds)

XValue schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.Y(shorthand=Undefined, aggregate=Undefined, axis=Undefined, bin=Undefined, field=Undefined, scale=Undefined, sort=Undefined, stack=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Y schema wrapper

Mapping(required=[shorthand])

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
axis (anyOf(Axis, None)) An object defining properties of axis’s gridlines, ticks and labels. If null, the axis for the encoding channel will be removed. __Default value:__ If undefined, default [axis properties](https://vega.github.io/vega-lite/docs/axis.html) are applied.
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
scale (anyOf(Scale, None)) An object defining properties of the channel’s scale, which is the function that transforms values in the data domain (numbers, dates, strings, etc) to visual values (pixels, colors, sizes) of the encoding channels. If null, the scale will be [disabled and the data value will be directly encoded](https://vega.github.io/vega-lite/docs/scale.html#disable). __Default value:__ If undefined, default [scale properties](https://vega.github.io/vega-lite/docs/scale.html) are applied.
sort (anyOf(SortOrder, SortField, None)) Sort order for the encoded field. Supported sort values include “ascending”, “descending” and null (no sorting). For fields with discrete domains, sort can also be a [sort field definition object](https://vega.github.io/vega-lite/docs/sort.html#sort-field). __Default value:__ “ascending”
stack (anyOf(StackOffset, None)) Type of stacking offset if the field should be stacked. stack is only applicable for x and y channels with continuous domains. For example, stack of y can be used to customize stacking for a vertical bar chart. stack can be one of the following values: - “zero”: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart). - “normalize” - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/> -“center” - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)). - null - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart. __Default value:__ zero for plots with all of the following conditions are true: (1) the mark is bar or area; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, null by default.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Y2(shorthand=Undefined, aggregate=Undefined, bin=Undefined, field=Undefined, timeUnit=Undefined, type=Undefined, **kwds)

Y2 schema wrapper

Mapping(required=[shorthand]) Definition object for a data field, its type and transformation of an encoding channel.

Attributes

shorthand (string) shorthand for field, aggregate, and type
aggregate (Aggregate) Aggregation function for the field (e.g., mean, sum, median, min, max, count). __Default value:__ undefined (None)
bin (anyOf(boolean, BinParams)) A flag for binning a quantitative field, or [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params). If true, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied. __Default value:__ false
field (anyOf(string, RepeatRef)) __Required.__ A string defining the name of the field from which to pull a data value or an object defining iterated values from the [repeat](https://vega.github.io/vega-lite/docs/repeat.html) operator. __Note:__ Dots (.) and brackets ([ and ]) can be used to access nested objects (e.g., “field”: “foo.bar” and “field”: “foo[‘bar’]”). If field names contain dots or brackets but are not nested, you can use ` to escape dots and brackets (e.g., `”a.b” and “a[0]”). See more details about escaping in the [field documentation](https://vega.github.io/vega-lite/docs/field.html). __Note:__ field is not required if aggregate is count.
timeUnit (TimeUnit) Time unit (e.g., year, yearmonth, month, hours) for a temporal field. or [a temporal field that gets casted as ordinal](https://vega.github.io/vega-lite/docs/type.html#cast). __Default value:__ undefined (None)
type (Type) The encoded field’s type of measurement (“quantitative”, “temporal”, “ordinal”, or “nominal”). It can also be a geo type (“latitude”, “longitude”, and “geojson”) when a [geographic projection](https://vega.github.io/vega-lite/docs/projection.html) is applied.
class altair.Y2Value(value, **kwds)

Y2Value schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.YValue(value, **kwds)

YValue schema wrapper

Mapping(required=[value]) Definition object for a constant value of an encoding channel.

Attributes

value (anyOf(float, string, boolean)) A constant value in visual domain (e.g., “red” / “#0099ff” for color, values between 0 to 1 for opacity).
class altair.curry(*args, **kwargs)

Curry a callable function

Enables partial application of arguments through calling a function with an incomplete set of arguments.

>>> def mul(x, y):
...     return x * y
>>> mul = curry(mul)
>>> double = mul(2)
>>> double(10)
20

Also supports keyword arguments

>>> @curry                  # Can use curry as a decorator
... def f(x, y, a=10):
...     return a * (x + y)
>>> add = f(a=1)
>>> add(2, 3)
5
See Also:
toolz.curried - namespace of curried functions
https://toolz.readthedocs.io/en/latest/curry.html
altair.binding(self, *args, **kwds)

A generic binding anyOf(VgCheckboxBinding, VgRadioBinding, VgSelectBinding, VgRangeBinding, VgGenericBinding)

altair.binding_checkbox(self, input=Undefined, element=Undefined, **kwds)

A checkbox binding Mapping(required=[input])

Attributes

input (enum(‘checkbox’))
element (string)
altair.binding_radio(self, input=Undefined, options=Undefined, element=Undefined, **kwds)

A radio button binding Mapping(required=[input, options])

Attributes

input (enum(‘radio’))
options (List(string))
element (string)
altair.binding_range(self, input=Undefined, element=Undefined, max=Undefined, min=Undefined, step=Undefined, **kwds)

A range binding Mapping(required=[input])

Attributes

input (enum(‘range’))
element (string)
max (float)
min (float)
step (float)
altair.binding_select(self, input=Undefined, options=Undefined, element=Undefined, **kwds)

A select binding Mapping(required=[input, options])

Attributes

input (enum(‘select’))
options (List(string))
element (string)
altair.condition(predicate, if_true, if_false, **kwargs)

A conditional attribute or encoding

Parameters:

predicate: NamedSelection, LogicalOperandPredicate, expr.Expression, dict, or string

the selection predicate or test predicate for the condition. if a string is passed, it will be treated as a test operand.

if_true:

the spec or object to use if the selection predicate is true

if_false:

the spec or object to use if the selection predicate is false

**kwargs:

additional keyword args are added to the resulting dict

Returns:

spec: dict or VegaLiteSchema

the spec that describes the condition

altair.hconcat(*charts, **kwargs)

Concatenate charts horizontally

altair.layer(*charts, **kwargs)

layer multiple charts

altair.list_datasets()

List the available datasets.

altair.load_dataset(name)

Load a dataset by name as a pandas.DataFrame.

altair.load_schema()

Load the json schema associated with this module’s functions

altair.parse_shorthand(shorthand, data=None)

Parse the shorthand expression for aggregation, field, and type.

These are of the form:

  • “col_name”
  • “col_name:O”
  • “average(col_name)”
  • “average(col_name):O”

Optionally, a dataframe may be supplied, from which the type will be inferred if not specified in the shorthand.

Parameters:

shorthand: str

Shorthand string of the form “agg(col):typ”

data : pd.DataFrame (optional)

Dataframe from which to infer types

Returns:

D : dict

Dictionary which always contains a ‘field’ key, and additionally contains an ‘aggregate’ and ‘type’ key depending on the input.

Examples

>>> data = pd.DataFrame({'foo': ['A', 'B', 'A', 'B'],
...                      'bar': [1, 2, 3, 4]})
>>> parse_shorthand('name')
{'field': 'name'}
>>> parse_shorthand('average(col)')  
{'aggregate': 'average', 'field': 'col'}
>>> parse_shorthand('foo:O')  
{'field': 'foo', 'type': 'ordinal'}
>>> parse_shorthand('min(foo):Q')  
{'aggregate': 'min', 'field': 'foo', 'type': 'quantitative'}
>>> parse_shorthand('foo', data)  
{'field': 'foo', 'type': 'nominal'}
>>> parse_shorthand('bar', data)  
{'field': 'bar', 'type': 'quantitative'}
>>> parse_shorthand('bar:O', data)  
{'field': 'bar', 'type': 'ordinal'}
>>> parse_shorthand('sum(bar)', data)  
{'aggregate': 'sum', 'field': 'bar', 'type': 'quantitative'}
>>> parse_shorthand('count()', data)  
{'aggregate': 'count', 'type': 'quantitative'}
altair.pipe(data, *funcs)

Pipe a value through a sequence of functions

I.e. pipe(data, f, g, h) is equivalent to h(g(f(data)))

We think of the value as progressing through a pipe of several transformations, much like pipes in UNIX

$ cat data | f | g | h

>>> double = lambda i: 2 * i
>>> pipe(3, double, str)
'6'
See Also:
compose thread_first thread_last
altair.repeat(repeater)

Tie a channel to the row or column within a repeated chart

The output of this should be passed to the field attribute of a channel.

Parameters:

repeater : {‘row’|’column’}

The repeater to tie the field to.

Returns:

repeat : RepeatRef object

altair.selection(name=None, type=Undefined, **kwds)

Create a named selection.

Parameters:

name : string (optional)

The name of the selection. If not specified, a unique name will be created.

type : string

The type of the selection: one of [“interval”, “single”, or “multi”]

**kwds :

additional keywords will be used to construct a SelectionDef instance that controls the selection.

Returns:

selection: NamedSelection

The selection object that can be used in chart creation.

altair.selection_interval(self, type=Undefined, bind=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, mark=Undefined, on=Undefined, resolve=Undefined, translate=Undefined, zoom=Undefined, **kwds)

Create a selection with type=’interval’ Mapping(required=[type])

Attributes

type (enum(‘interval’))
bind (enum(‘scales’)) Establishes a two-way binding between the interval selection and the scales used within the same view. This allows a user to interactively pan and zoom the view.
empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
mark (BrushConfig) An interval selection also adds a rectangle mark to depict the extents of the interval. The mark property can be used to customize the appearance of the mark.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
translate (anyOf(string, boolean)) When truthy, allows a user to interactively move an interval selection back-and-forth. Can be true, false (to disable panning), or a [Vega event stream definition](https://vega.github.io/vega/docs/event-streams/) which must include a start and end event to trigger continuous panning. __Default value:__ true, which corresponds to [mousedown, window:mouseup] > window:mousemove! which corresponds to clicks and dragging within an interval selection to reposition it.
zoom (anyOf(string, boolean)) When truthy, allows a user to interactively resize an interval selection. Can be true, false (to disable zooming), or a [Vega event stream definition](https://vega.github.io/vega/docs/event-streams/). Currently, only wheel events are supported. __Default value:__ true, which corresponds to wheel!.
altair.selection_multi(self, type=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, nearest=Undefined, on=Undefined, resolve=Undefined, toggle=Undefined, **kwds)

Create a selection with type=’multi’ Mapping(required=[type])

Attributes

type (enum(‘multi’))
empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
nearest (boolean) When true, an invisible voronoi diagram is computed to accelerate discrete selection. The data value _nearest_ the mouse cursor is added to the selection. See the [nearest transform](nearest.html) documentation for more information.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
toggle (anyOf(string, boolean)) Controls whether data values should be toggled or only ever inserted into multi selections. Can be true, false (for insertion only), or a [Vega expression](https://vega.github.io/vega/docs/expressions/). __Default value:__ true, which corresponds to event.shiftKey (i.e., data values are toggled when a user interacts with the shift-key pressed). See the [toggle transform](toggle.html) documentation for more information.
altair.selection_single(self, type=Undefined, bind=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, nearest=Undefined, on=Undefined, resolve=Undefined, **kwds)

Create a selection with type=’single’ Mapping(required=[type])

Attributes

type (enum(‘single’))
bind (anyOf(VgBinding, Mapping(required=[]))) Establish a two-way binding between a single selection and input elements (also known as dynamic query widgets). A binding takes the form of Vega’s [input element binding definition](https://vega.github.io/vega/docs/signals/#bind) or can be a mapping between projected field/encodings and binding definitions. See the [bind transform](bind.html) documentation for more information.
empty (enum(‘all’, ‘none’)) By default, all data values are considered to lie within an empty selection. When set to none, empty selections contain no data values.
encodings (List(SingleDefChannel)) An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.
fields (List(string)) An array of field names whose values must match for a data tuple to fall within the selection.
nearest (boolean) When true, an invisible voronoi diagram is computed to accelerate discrete selection. The data value _nearest_ the mouse cursor is added to the selection. See the [nearest transform](nearest.html) documentation for more information.
on (VgEventStream) A [Vega event stream](https://vega.github.io/vega/docs/event-streams/) (object or selector) that triggers the selection. For interval selections, the event stream must specify a [start and end](https://vega.github.io/vega/docs/event-streams/#between-filters).
resolve (SelectionResolution) With layered and multi-view displays, a strategy that determines how selections’ data queries are resolved when applied in a filter transform, conditional encoding rule, or scale domain.
altair.topo_feature(url, feature, **kwargs)

A convenience function for extracting features from a topojson url

Parameters:

url : string

An URL from which to load the data set.

feature : string

The name of the TopoJSON object set to convert to a GeoJSON feature collection. For example, in a map of the world, there may be an object set named “countries”. Using the feature property, we can extract this set and generate a GeoJSON feature object for each country.

**kwargs :

additional keywords passed to TopoDataFormat

altair.value(value, **kwargs)

Specify a value for use in an encoding

altair.vconcat(*charts, **kwargs)

Concatenate charts vertically

altair.limit_rows

Raise MaxRowsError if the data model has more than max_rows.

altair.sample

Reduce the size of the data model by sampling without replacement.

altair.to_csv

Write the data model to a .csv file and return a url based data model.

altair.to_json

Write the data model to a .json file and return a url based data model.

altair.to_values

Replace a DataFrame by a data model with values.

Vega Expressions

Tools for creating transform & filter expressions with a python syntax

class altair.expr.Expression(*args, **kwds)

Base object for enabling build-up of Javascript expressions using a Python syntax. Calling repr(obj) will return a Javascript representation of the object and the operations it encodes.