class altair.JsonDataFormat(parse=Undefined, property=Undefined, type=Undefined, **kwds)

JsonDataFormat schema wrapper


parseanyOf(Parse, None)

If set to null, disable type inference based on the spec and only use type inference based on the data. 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", "date", or null (do not parse the field)). 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(). For Specific date formats can be provided (e.g., {foo: "date:'%m%d%Y'"} ), using the d3-time-format syntax. UTC date format parsing is supported similarly (e.g., {foo: "utc:'%m%d%Y'"} ). See more about UTC time


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 of input data: "json", "csv", "tsv", "dsv".

Default value: The default format type is determined by the extension of the file URL. If no extension is detected, "json" will be used by default.

__init__(parse=Undefined, property=Undefined, type=Undefined, **kwds)


__init__([parse, property, type])

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, ignore, context, indent, ...])

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