streams Module

streams Module

The streams module defines the streams API that allows visualizations to generate and respond to events, originating either in Python on the server-side or in Javascript in the Jupyter notebook (client-side).

class holoviews.streams.BoundsX(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A stream representing the bounds of a box selection as an tuple of the left and right coordinates.

Parameter Definitions

---

boundsx = Tuple(allow_None=True, constant=True, label='Boundsx', length=2)

Bounds defined as (left, right) tuple.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.BoundsXY(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A stream representing the bounds of a box selection as an tuple of the left, bottom, right and top coordinates.

Parameter Definitions

---

bounds = Tuple(allow_None=True, constant=True, label='Bounds', length=4)

Bounds defined as (left, bottom, right, top) tuple.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.BoundsY(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A stream representing the bounds of a box selection as an tuple of the bottom and top coordinates.

Parameter Definitions

---

boundsy = Tuple(allow_None=True, constant=True, label='Boundsy', length=2)

Bounds defined as (bottom, top) tuple.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.BoxEdit(empty_value=None, num_objects=0, styles=None, tooltip=None, **params)

Bases: CDSStream

Attaches a BoxEditTool and syncs the datasource.

empty_value: int/float/string/None

The value to insert on non-position columns when adding a new box

num_objects: int

The number of boxes that can be drawn before overwriting the oldest drawn box.

styles: dict

A dictionary specifying lists of styles to cycle over whenever a new box glyph is drawn.

tooltip: str

An optional tooltip to override the default

Parameter Definitions

---

data = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Data')

Data synced from Bokeh ColumnDataSource supplied as a dictionary of columns, where each column is a list of values (for point-like data) or list of lists of values (for path-like data).

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Buffer(data, length=1000, index=True, following=True, **params)

Bases: Pipe

Buffer allows streaming and accumulating incoming chunks of rows from tabular datasets. The data may be in the form of a pandas DataFrame, 2D arrays of rows and columns or dictionaries of column arrays. Buffer will accumulate the last N rows, where N is defined by the specified length. The accumulated data is then made available via the data parameter.

A Buffer may also be instantiated with a streamz.StreamingDataFrame or a streamz.StreamingSeries, it will automatically subscribe to events emitted by a streamz object.

When streaming a DataFrame will reset the DataFrame index by default making it available to HoloViews elements as dimensions, this may be disabled by setting index=False.

The following argument determines whether any plot which is subscribed to this stream will update the axis ranges when an update is pushed. This makes it possible to control whether zooming is allowed while streaming.

Parameter Definitions

---

data = Parameter(allow_None=True, constant=True, label='Data')

Arbitrary data being streamed to a DynamicMap callback.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear()

Clears the data in the stream

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

send(data)

A convenience method to send an event with data without supplying a keyword.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

Overrides update to concatenate streamed data up to defined length.

verify(x)

Verify consistency of dataframes that pass through this stream

class holoviews.streams.CDSStream(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A Stream that syncs a bokeh ColumnDataSource with python.

Parameter Definitions

---

data = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Data')

Data synced from Bokeh ColumnDataSource supplied as a dictionary of columns, where each column is a list of values (for point-like data) or list of lists of values (for path-like data).

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Counter(rename=None, source=None, subscribers=None, linked=False, transient=False, **params)

Bases: Stream

Simple stream that automatically increments an integer counter parameter every time it is updated.

Parameter Definitions

---

counter = Integer(bounds=(0, None), constant=True, default=0, inclusive_bounds=(True, True), label='Counter')

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.CrossFilterSet(selection_streams=(), mode='intersection', index_cols=None, **params)

Bases: Derived

Parameter Definitions

---

selection_expr = Parameter(allow_None=True, constant=True, label='Selection expr')

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

append_input_stream(stream)

Add a new input stream

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

property constants

Dict of constants for this instance that should be passed to transform_function

Constant values must not change in response to changes in the values of the input streams. They may, however, change in response to other stream property updates. For example, these values may change if the Stream’s source element changes

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod transform_function(stream_values, constants)

Pure function that transforms input stream param values into the param values of this Derived stream.

Args:

stream_values: list of dict

Current values of the stream params for each input_stream

constants: dict

Constants as returned by the constants property of an instance of this stream type.

Returns: dict

dict of new Stream values where the keys match this stream’s params

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.CurveEdit(style=None, tooltip=None, **params)

Bases: PointDraw

Attaches a PointDraw to the plot which allows editing the Curve when selected.

style: dict

A dictionary specifying the style of the vertices.

tooltip: str

An optional tooltip to override the default

Parameter Definitions

---

data = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Data')

Data synced from Bokeh ColumnDataSource supplied as a dictionary of columns, where each column is a list of values (for point-like data) or list of lists of values (for path-like data).

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Derived(input_streams, exclusive=False, **params)

Bases: Stream

A Stream that watches the parameters of one or more input streams and produces a result that is a pure function of the input stream values.

If exclusive=True, then all streams except the most recently updated are cleared.

Parameter Definitions

---

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

append_input_stream(stream)

Add a new input stream

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

property constants

Dict of constants for this instance that should be passed to transform_function

Constant values must not change in response to changes in the values of the input streams. They may, however, change in response to other stream property updates. For example, these values may change if the Stream’s source element changes

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod transform_function(stream_values, constants)

Pure function that transforms input stream param values into the param values of this Derived stream.

Args:

stream_values: list of dict

Current values of the stream params for each input_stream

constants: dict

Constants as returned by the constants property of an instance of this stream type.

Returns: dict

dict of new Stream values where the keys match this stream’s params

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.DoubleTap(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: PointerXY

The x/y-position of a double-tap or -click in data coordinates.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Draw(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: PointerXY

A series of updating x/y-positions when drawing, together with the current stroke count

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

stroke_count = Integer(constant=True, default=0, inclusive_bounds=(True, True), label='Stroke count')

The current drawing stroke count. Increments every time a new stroke is started.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.FreehandDraw(empty_value=None, num_objects=0, styles=None, tooltip=None, **params)

Bases: CDSStream

Attaches a FreehandDrawTool and syncs the datasource.

empty_value: int/float/string/None

The value to insert on non-position columns when adding a new polygon

num_objects: int

The number of polygons that can be drawn before overwriting the oldest polygon.

styles: dict

A dictionary specifying lists of styles to cycle over whenever a new freehand glyph is drawn.

tooltip: str

An optional tooltip to override the default

Parameter Definitions

---

data = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Data')

Data synced from Bokeh ColumnDataSource supplied as a dictionary of columns, where each column is a list of values (for point-like data) or list of lists of values (for path-like data).

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.History(input_stream, **params)

Bases: Stream

A Stream that maintains a history of the values of a single input stream

Parameter Definitions

---

values = List(bounds=(0, None), constant=True, default=[], label='Values')

List containing the historical values of the input stream

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Lasso(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A stream representing a lasso selection in 2D space as a two-column array of coordinates.

Parameter Definitions

---

geometry = Array(allow_None=True, class_=<class 'numpy.ndarray'>, constant=True, label='Geometry')

The coordinates of the lasso geometry as a two-column array.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.LinkedStream(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: Stream

A LinkedStream indicates is automatically linked to plot interactions on a backend via a Renderer. Not all backends may support dynamically supplying stream data.

Parameter Definitions

---

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.MouseEnter(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: PointerXY

The x/y-position where the mouse/cursor entered the plot area in data coordinates.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.MouseLeave(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: PointerXY

The x/y-position where the mouse/cursor entered the plot area in data coordinates.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.MultiAxisTap(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

The x/y-positions of a tap or click in data coordinates.

Parameter Definitions

---

xs = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Xs')

Pointer positions along the x-axes in data coordinates

ys = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Ys')

Pointer positions along the y-axes in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PanEnd(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: PointerXY

The x/y position of a the end of a pan event in data coordinates.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.ParamMethod(parameterized, parameters=None, watch=True, **params)

Bases: Params

A Stream that watches the parameter dependencies on a method of a parameterized class and triggers when one of the parameters change.

Parameter Definitions

---

parameterized = ClassSelector(allow_None=True, class_=(<class 'param.parameterized.Parameterized'>, <class 'param.parameterized.ParameterizedMetaclass'>), constant=True, label='Parameterized')

Parameterized instance to watch for parameter changes.

parameters = List(bounds=(0, None), constant=True, default=[], label='Parameters')

Parameters on the parameterized to watch.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

classmethod from_params(params, **kwargs)

Returns Params streams given a dictionary of parameters

Args:

params (dict): Dictionary of parameters

Returns:

List of Params streams

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

unwatch()

Stop watching parameters.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Params(parameterized=None, parameters=None, watch=True, watch_only=False, **params)

Bases: Stream

A Stream that watches the changes in the parameters of the supplied Parameterized objects and triggers when they change.

Parameter Definitions

---

parameterized = ClassSelector(allow_None=True, class_=(<class 'param.parameterized.Parameterized'>, <class 'param.parameterized.ParameterizedMetaclass'>), constant=True, label='Parameterized')

Parameterized instance to watch for parameter changes.

parameters = List(bounds=(0, None), constant=True, default=[], label='Parameters')

Parameters on the parameterized to watch.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

classmethod from_params(params, **kwargs)

Returns Params streams given a dictionary of parameters

Args:

params (dict): Dictionary of parameters

Returns:

List of Params streams

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

unwatch()

Stop watching parameters.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Pipe(data=None, memoize=False, **params)

Bases: Stream

A Stream used to pipe arbitrary data to a callback. Unlike other streams memoization can be disabled for a Pipe stream (and is disabled by default).

Parameter Definitions

---

data = Parameter(allow_None=True, constant=True, label='Data')

Arbitrary data being streamed to a DynamicMap callback.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

send(data)

A convenience method to send an event with data without supplying a keyword.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PlotReset(*args, **params)

Bases: LinkedStream

A stream signalling when a plot reset event has been triggered.

Parameter Definitions

---

resetting = Boolean(constant=True, default=False, label='Resetting')

Whether a reset event is being signalled.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PlotSize(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

Returns the dimensions of a plot once it has been displayed.

Parameter Definitions

---

width = Integer(allow_None=True, constant=True, inclusive_bounds=(True, True), label='Width')

The width of the plot in pixels

height = Integer(allow_None=True, constant=True, inclusive_bounds=(True, True), label='Height')

The height of the plot in pixels

scale = Number(constant=True, default=1.0, inclusive_bounds=(True, True), label='Scale')

Scale factor to scale width and height values reported by the stream

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PointDraw(empty_value=None, add=True, drag=True, num_objects=0, styles=None, tooltip=None, **params)

Bases: CDSStream

Attaches a PointDrawTool and syncs the datasource.

add: boolean

Whether to allow adding new Points

drag: boolean

Whether to enable dragging of Points

empty_value: int/float/string/None

The value to insert on non-position columns when adding a new polygon

num_objects: int

The number of polygons that can be drawn before overwriting the oldest polygon.

styles: dict

A dictionary specifying lists of styles to cycle over whenever a new Point glyph is drawn.

tooltip: str

An optional tooltip to override the default

Parameter Definitions

---

data = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Data')

Data synced from Bokeh ColumnDataSource supplied as a dictionary of columns, where each column is a list of values (for point-like data) or list of lists of values (for path-like data).

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PointerX(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A pointer position along the x-axis in data coordinates which may be a numeric or categorical dimension.

With the appropriate plotting backend, this corresponds to the position of the mouse/trackpad cursor. If the pointer is outside the plot bounds, the position is set to None.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PointerXY(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A pointer position along the x- and y-axes in data coordinates which may numeric or categorical dimensions.

With the appropriate plotting backend, this corresponds to the position of the mouse/trackpad pointer. If the pointer is outside the plot bounds, the position values are set to None.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PointerY(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A pointer position along the y-axis in data coordinates which may be a numeric or categorical dimension.

With the appropriate plotting backend, this corresponds to the position of the mouse/trackpad pointer. If the pointer is outside the plot bounds, the position is set to None.

Parameter Definitions

---

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PolyDraw(empty_value=None, drag=True, num_objects=0, show_vertices=False, vertex_style=None, styles=None, tooltip=None, **params)

Bases: CDSStream

Attaches a PolyDrawTool and syncs the datasource.

drag: boolean

Whether to enable dragging of polygons and paths

empty_value: int/float/string/None

The value to insert on non-position columns when adding a new polygon

num_objects: int

The number of polygons that can be drawn before overwriting the oldest polygon.

show_vertices: boolean

Whether to show the vertices when a polygon is selected

styles: dict

A dictionary specifying lists of styles to cycle over whenever a new Poly glyph is drawn.

tooltip: str

An optional tooltip to override the default

vertex_style: dict

A dictionary specifying the style options for the vertices. The usual bokeh style options apply, e.g. fill_color, line_alpha, size, etc.

Parameter Definitions

---

data = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Data')

Data synced from Bokeh ColumnDataSource supplied as a dictionary of columns, where each column is a list of values (for point-like data) or list of lists of values (for path-like data).

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PolyEdit(vertex_style=None, shared=True, **params)

Bases: PolyDraw

Attaches a PolyEditTool and syncs the datasource.

shared: boolean

Whether PolyEditTools should be shared between multiple elements

tooltip: str

An optional tooltip to override the default

vertex_style: dict

A dictionary specifying the style options for the vertices. The usual bokeh style options apply, e.g. fill_color, line_alpha, size, etc.

Parameter Definitions

---

data = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Data')

Data synced from Bokeh ColumnDataSource supplied as a dictionary of columns, where each column is a list of values (for point-like data) or list of lists of values (for path-like data).

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.PressUp(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: PointerXY

The x/y position of a mouse pressup event in data coordinates.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.RangeX(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

Axis range along x-axis in data coordinates.

Parameter Definitions

---

x_range = Tuple(allow_None=True, constant=True, label='X range', length=2)

Range of the x-axis of a plot in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.RangeXY(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

Axis ranges along x- and y-axis in data coordinates.

Parameter Definitions

---

x_range = Tuple(allow_None=True, constant=True, label='X range', length=2)

Range of the x-axis of a plot in data coordinates

y_range = Tuple(allow_None=True, constant=True, label='Y range', length=2)

Range of the y-axis of a plot in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.RangeY(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

Axis range along y-axis in data coordinates.

Parameter Definitions

---

y_range = Tuple(allow_None=True, constant=True, label='Y range', length=2)

Range of the y-axis of a plot in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.SelectMode(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

Parameter Definitions

---

mode = Selector(constant=True, default='replace', label='Mode', names={}, objects=['replace', 'append', 'intersect', 'subtract'])

Defines what should happen when a new selection is made. The default is to replace the existing selection. Other options are to append to theselection, intersect with it or subtract from it.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Selection1D(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: LinkedStream

A stream representing a 1D selection of objects by their index.

Parameter Definitions

---

index = List(allow_None=True, bounds=(0, None), constant=True, default=[], label='Index')

Indices into a 1D datastructure.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.SelectionExpr(source, include_region=True, **params)

Bases: Derived

Parameter Definitions

---

selection_expr = Parameter(allow_None=True, constant=True, label='Selection expr')

bbox = Dict(allow_None=True, class_=<class 'dict'>, constant=True, label='Bbox')

region_element = Parameter(allow_None=True, constant=True, label='Region element')

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

append_input_stream(stream)

Add a new input stream

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

property constants

Dict of constants for this instance that should be passed to transform_function

Constant values must not change in response to changes in the values of the input streams. They may, however, change in response to other stream property updates. For example, these values may change if the Stream’s source element changes

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod transform_function(stream_values, constants)

Pure function that transforms input stream param values into the param values of this Derived stream.

Args:

stream_values: list of dict

Current values of the stream params for each input_stream

constants: dict

Constants as returned by the constants property of an instance of this stream type.

Returns: dict

dict of new Stream values where the keys match this stream’s params

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.SelectionExprSequence(source, mode='overwrite', include_region=True, **params)

Bases: Derived

Parameter Definitions

---

selection_expr = Parameter(allow_None=True, constant=True, label='Selection expr')

region_element = Parameter(allow_None=True, constant=True, label='Region element')

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

append_input_stream(stream)

Add a new input stream

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

property constants

Dict of constants for this instance that should be passed to transform_function

Constant values must not change in response to changes in the values of the input streams. They may, however, change in response to other stream property updates. For example, these values may change if the Stream’s source element changes

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod transform_function(stream_values, constants)

Pure function that transforms input stream param values into the param values of this Derived stream.

Args:

stream_values: list of dict

Current values of the stream params for each input_stream

constants: dict

Constants as returned by the constants property of an instance of this stream type.

Returns: dict

dict of new Stream values where the keys match this stream’s params

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.SelectionXY(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: BoundsXY

A stream representing the selection along the x-axis and y-axis. Unlike a BoundsXY stream, this stream returns range or categorical selections.

Parameter Definitions

---

bounds = Tuple(allow_None=True, constant=True, label='Bounds', length=4)

Bounds defined as (left, bottom, right, top) tuple.

x_selection = ClassSelector(allow_None=True, class_=(<class 'tuple'>, <class 'list'>), constant=True, label='X selection')

The current selection along the x-axis, either a numerical range defined as a tuple or a list of categories.

y_selection = ClassSelector(allow_None=True, class_=(<class 'tuple'>, <class 'list'>), constant=True, label='Y selection')

The current selection along the y-axis, either a numerical range defined as a tuple or a list of categories.

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.SingleTap(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: PointerXY

The x/y-position of a single tap or click in data coordinates.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Stream(rename=None, source=None, subscribers=None, linked=False, transient=False, **params)

Bases: Parameterized

A Stream is simply a parameterized object with parameters that change over time in response to update events and may trigger downstream events on its subscribers. The Stream parameters can be updated using the update method, which will optionally trigger the stream. This will notify the subscribers which may be supplied as a list of callables or added later using the add_subscriber method. The subscribers will be passed a dictionary mapping of the parameters of the stream, which are available on the instance as the contents.

Depending on the plotting backend certain streams may interactively subscribe to events and changes by the plotting backend. For this purpose use the LinkedStream baseclass, which enables the linked option by default. A source for the linking may be supplied to the constructor in the form of another viewable object specifying which part of a plot the data should come from.

The transient option allows treating stream events as discrete updates, resetting the parameters to their default after the stream has been triggered. A downstream callback can therefore determine whether a stream is active by checking whether the stream values match the default (usually None).

The Stream class is meant for subclassing and subclasses should generally add one or more parameters but may also override the transform and reset method to preprocess parameters before they are passed to subscribers and reset them using custom logic respectively.

Parameter Definitions

---

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

class holoviews.streams.Tap(linked=True, popup=None, popup_position='top_right', popup_anchor=None, **params)

Bases: PointerXY

The x/y-position of a tap or click in data coordinates.

Parameter Definitions

---

x = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='X')

Pointer position along the x-axis in data coordinates

y = ClassSelector(allow_None=True, class_=(<class 'numbers.Number'>, <class 'str'>, <class 'tuple'>, <class 'numpy.datetime64'>, <class 'datetime.datetime'>, <class 'datetime.date'>, <class 'datetime.time'>, <class 'pandas._libs.tslibs.timestamps.Timestamp'>, <class 'pandas.core.dtypes.dtypes.DatetimeTZDtype'>, <class 'pandas._libs.tslibs.period.Period'>, <class 'cftime._cftime.datetime'>), constant=True, label='Y')

Pointer position along the y-axis in data coordinates

add_subscriber(subscriber, precedence=0)

Register a callable subscriber to this stream which will be invoked either when event is called or when this stream is passed to the trigger classmethod.

Precedence allows the subscriber ordering to be controlled. Users should only add subscribers with precedence between zero and one while HoloViews itself reserves the use of higher precedence values. Subscribers with high precedence are invoked later than ones with low precedence.

clear(policy='all')

Clear all subscribers registered to this stream.

The default policy of ‘all’ clears all subscribers. If policy is set to ‘user’, only subscribers defined by the user are cleared (precedence between zero and one). A policy of ‘internal’ clears subscribers with precedence greater than unity used internally by HoloViews.

clone()

Return new stream with identical properties and no subscribers

classmethod define(name, **kwargs)

Utility to quickly and easily declare Stream classes. Designed for interactive use such as notebooks and shouldn’t replace parameterized class definitions in source code that is imported.

Takes a stream class name and a set of keywords where each keyword becomes a parameter. If the value is already a parameter, it is simply used otherwise the appropriate parameter type is inferred and declared, using the value as the default.

Supported types: bool, int, float, str, dict, tuple and list

event(**kwargs)

Update the stream parameters and trigger an event.

property hashkey

The object the memoization hash is computed from. By default returns the stream contents but can be overridden to provide a custom hash key.

rename(**mapping)

The rename method allows stream parameters to be allocated to new names to avoid clashes with other stream parameters of the same name. Returns a new clone of the stream instance with the specified name mapping.

reset()

Resets stream parameters to their defaults.

property subscribers

Property returning the subscriber list

transform()

Method that can be overwritten by subclasses to process the parameter values before renaming is applied. Returns a dictionary of transformed parameters.

classmethod trigger(streams)

Given a list of streams, collect all the stream parameters into a dictionary and pass it to the union set of subscribers.

Passing multiple streams at once to trigger can be useful when a subscriber may be set multiple times across streams but only needs to be called once.

update(**kwargs)

The update method updates the stream parameters (without any renaming applied) in response to some event. If the stream has a custom transform method, this is applied to transform the parameter values accordingly.

To update and trigger, use the event method.

holoviews.streams.streams_list_from_dict(streams)

Converts a streams dictionary into a streams list

holoviews.streams.triggering_streams(streams)

Temporarily declares the streams as being in a triggered state. Needed by DynamicMap to determine whether to memoize on a Callable, i.e. if a stream has memoization disabled and is in triggered state Callable should disable lookup in the memoization cache. This is done by the dynamicmap_memoization context manager.