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class altair.UnitSpec(mark=Undefined, data=Undefined, description=Undefined, encoding=Undefined, name=Undefined, params=Undefined, projection=Undefined, title=Undefined, transform=Undefined, **kwds)#

UnitSpec schema wrapper Base interface for a unit (single-view) specification.

markstr, dict, Mark, AnyMark, BoxPlot, MarkDef, ErrorBar, ErrorBand, BoxPlotDef, ErrorBarDef, ErrorBandDef, CompositeMark, CompositeMarkDef, Literal[‘arc’, ‘area’, ‘bar’, ‘image’, ‘line’, ‘point’, ‘rect’, ‘rule’, ‘text’, ‘tick’, ‘trail’, ‘circle’, ‘square’, ‘geoshape’]

A string describing the mark type (one of "bar", "circle", "square", "tick", "line", "area", "point", "rule", "geoshape", and "text" ) or a mark definition object.

datadict, None, Data, UrlData, Generator, NamedData, DataSource, InlineData, SphereGenerator, SequenceGenerator, GraticuleGenerator

An object describing the data source. Set to null to ignore the parent’s data source. If no data is set, it is derived from the parent.


Description of this mark for commenting purpose.

encodingdict, Encoding

A key-value mapping between encoding channels and definition of fields.


Name of the visualization for later reference.

paramsSequence[dict, SelectionParameter]

An array of parameters that may either be simple variables, or more complex selections that map user input to data queries.

projectiondict, Projection

An object defining properties of geographic projection, which will be applied to shape path for "geoshape" marks and to latitude and "longitude" channels for other marks.

titlestr, dict, Text, Sequence[str], TitleParams

Title for the plot.

transformSequence[dict, Transform, BinTransform, FoldTransform, LoessTransform, PivotTransform, StackTransform, ExtentTransform, FilterTransform, ImputeTransform, LookupTransform, SampleTransform, WindowTransform, DensityTransform, FlattenTransform, QuantileTransform, TimeUnitTransform, AggregateTransform, CalculateTransform, RegressionTransform, JoinAggregateTransform]

An array of data transformations such as filter and new field calculation.

__init__(mark=Undefined, data=Undefined, description=Undefined, encoding=Undefined, name=Undefined, params=Undefined, projection=Undefined, title=Undefined, transform=Undefined, **kwds)#


__init__([mark, data, description, ...])

copy([deep, ignore])

Return a copy of the object

from_dict(dct[, validate, _wrapper_classes])

Construct class from a dictionary representation

from_json(json_string[, validate])

Instantiate the object from a valid JSON string


Resolve references in the context of this object's schema or root schema.

to_dict([validate, ignore, context])

Return a dictionary representation of the object

to_json([validate, indent, sort_keys, ...])

Emit the JSON representation for this object as a string.

validate(instance[, schema])

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

validate_property(name, value[, schema])

Validate a property against property schema in the context of the rootschema