class altair.WindowFieldDef(op=Undefined, field=Undefined, param=Undefined, **kwds)

WindowFieldDef schema wrapper

Mapping(required=[op, as])

opanyOf(AggregateOp, WindowOnlyOp)

The window or aggregation operation to apply within a window (e.g., "rank", "lead", "sum", "average" or "count" ). See the list of all supported operations here.


The data field for which to compute the aggregate or window function. This can be omitted for window functions that do not operate over a field such as "count", "rank", "dense_rank".


Parameter values for the window functions. Parameter values can be omitted for operations that do not accept a parameter.

See the list of all supported operations and their parameters here.


The output name for the window operation.

__init__(op=Undefined, field=Undefined, param=Undefined, **kwds)


__init__([op, field, param])

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