altair.SingleSelection

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

SingleSelection schema wrapper

Mapping(required=[type])

Attributes

typeenum(‘single’)

Determines the default event processing and data query for the selection. Vega-Lite currently supports three selection types:

• "single" – to select a single discrete data value on click.

• "multi" – to select multiple discrete data value; the first value is selected on click and additional values toggled on shift- click.

• "interval" – to select a continuous range of data values on drag.

bindanyOf(Binding, Mapping(required=[]), LegendBinding)

When set, a selection is populated by input elements (also known as dynamic query widgets) or by interacting with the corresponding legend. Direct manipulation interaction is disabled by default; to re-enable it, set the selection’s on property.

Legend bindings are restricted to selections that only specify a single field or encoding.

Query widget binding takes the form of Vega’s input element binding definition or can be a mapping between projected field/encodings and binding definitions.

See also: bind documentation.

clearanyOf(Stream, string, boolean)

Clears the selection, emptying it of all values. Can be a Event Stream or false to disable.

Default value: dblclick.

See also: clear documentation.

emptyenum(‘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.

encodingsList(SingleDefUnitChannel)

An array of encoding channels. The corresponding data field values must match for a data tuple to fall within the selection.

See also: encodings documentation.

fieldsList(FieldName)

An array of field names whose values must match for a data tuple to fall within the selection.

See also: fields documentation.

initSelectionInitMapping

Initialize the selection with a mapping between projected channels or field names and initial values.

See also: init documentation.

nearestboolean

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 also: nearest documentation.

onanyOf(Stream, string)

A Vega event stream (object or selector) that triggers the selection. For interval selections, the event stream must specify a start and end.

resolveSelectionResolution

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.

See also: resolve documentation.

__init__(self, type=Undefined, bind=Undefined, clear=Undefined, empty=Undefined, encodings=Undefined, fields=Undefined, init=Undefined, nearest=Undefined, on=Undefined, resolve=Undefined, **kwds)

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__(self[, type, bind, clear, empty, …])	Initialize self.
copy(self[, 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([schema])	Resolve references in the context of this object’s schema or root schema.
to_dict(self[, validate, ignore, context])	Return a dictionary representation of the object
to_json(self[, validate, ignore, context, …])	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

copy(self, deep=True, ignore=())

Return a copy of the object

Parameters

deepboolean or list, optional

If True (default) then return a deep copy of all dict, list, and SchemaBase objects within the object structure. If False, then only copy the top object. If a list or iterable, then only copy the listed attributes.

ignorelist, 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

dctdictionary

The dict from which to construct the class

validateboolean

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

_wrapper_classeslist (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

objSchema 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_stringstring

The string containing a valid JSON chart specification.

validateboolean

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

**kwargs :

Additional keyword arguments are passed to json.loads

Returns

chartChart object

The altair Chart object built from the specification.

classmethod resolve_references(schema=None)

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

to_dict(self, validate=True, ignore=None, context=None)

Return a dictionary representation of the object

Parameters

validateboolean 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.

ignorelist

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

contextdict (optional)

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

Returns

dctdictionary

The dictionary representation of this object

Raises

jsonschema.ValidationError :

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

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

Emit the JSON representation for this object as a string.

Parameters

validateboolean 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.

ignorelist

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

contextdict (optional)

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

indentinteger, default 2

the number of spaces of indentation to use

sort_keysboolean, default True

if True, sort keys in the output

**kwargs

Additional keyword arguments are passed to json.dumps()

Returns

specstring

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.

classmethod validate_property(name, value, schema=None)

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