param Module

param Module

Defines the Param pane which converts Parameterized classes into a set of widgets.

class panel.param.JSONInit(*, fig, holomap, widgets, fps, max_frames, size, dpi, filename, info, css, widget_location)[source]

Bases: param.parameterized.Parameterized

Callable that can be passed to Widgets.initializer to set Parameter values using JSON. There are three approaches that may be used: 1. If the json_file argument is specified, this takes precedence. 2. The JSON file path can be specified via an environment variable. 3. The JSON can be read directly from an environment variable. Here is an easy example of setting such an environment variable on the commandline: PARAM_JSON_INIT=’{“p1”:5}’ jupyter notebook This addresses any JSONInit instances that are inspecting the default environment variable called PARAM_JSON_INIT, instructing it to set the ‘p1’ parameter to 5.

varname = param.String(default=’PARAM_JSON_INIT’)

The name of the environment variable containing the JSON specification.

target = param.String()

Optional key in the JSON specification dictionary containing the desired parameter values.

json_file = param.String()

Optional path to a JSON file containing the parameter settings.

class panel.param.Param(object=None, **params)[source]

Bases: panel.pane.base.PaneBase

Param panes render a Parameterized class to a set of widgets which are linked to the parameter values on the class.

Parameters inherited from:

panel.viewable.Layoutable: align, aspect_ratio, background, css_classes, min_width, min_height, max_width, max_height, margin, width_policy, height_policy, sizing_mode

panel.pane.base.PaneBase: object

width = param.Integer(bounds=(0, None), default=300, inclusive_bounds=(True, True))

Width of widgetbox the parameter widgets are displayed in.

height = param.Integer(bounds=(0, None), inclusive_bounds=(True, True))

Height of widgetbox the parameter widgets are displayed in.

default_layout = param.ClassSelector(class_=<class ‘panel.layout.Panel’>, default=<class ‘panel.layout.Column’>)

Defines the layout the model(s) returned by the pane will be placed in.

display_threshold = param.Number(default=0, inclusive_bounds=(True, True))

Parameters with precedence below this value are not displayed.

default_precedence = param.Number(default=1e-08, inclusive_bounds=(True, True))

Precedence value to use for parameters with no declared precedence. By default, zero predecence is available for forcing some parameters to the top of the list, and other values above the default_precedence values can be used to sort or group parameters arbitrarily.

expand = param.Boolean(bounds=(0, 1), default=False)

Whether parameterized subobjects are expanded or collapsed on instantiation.

expand_button = param.Boolean(bounds=(0, 1))

Whether to add buttons to expand and collapse sub-objects.

expand_layout = param.Parameter(default=<class ‘panel.layout.Column’>)

Layout to expand sub-objects into.

initializer = param.Callable()

User-supplied function that will be called on initialization, usually to update the default Parameter values of the underlying parameterized object.

parameters = param.List(bounds=(0, None), default=[])

If set this serves as a whitelist of parameters to display on the supplied Parameterized object.

show_labels = param.Boolean(bounds=(0, 1), default=True)

Whether to show labels for each widget

show_name = param.Boolean(bounds=(0, 1), default=True)

Whether to show the parameterized object’s name

widgets = param.Dict(class_=<class ‘dict’>)

Dictionary of widget overrides, mapping from parameter name to widget class.

add_periodic_callback(callback, period=500, count=None, timeout=None, start=True)

Schedules a periodic callback to be run at an interval set by the period. Returns a PeriodicCallback object with the option to stop and start the callback.

Parameters
  • callback (callable) – Callable function to be executed at periodic interval.

  • period (int) – Interval in milliseconds at which callback will be executed.

  • count (int) – Maximum number of times callback will be invoked.

  • timeout (int) – Timeout in seconds when the callback should be stopped.

  • start (boolean (default=True)) – Whether to start callback immediately.

Returns

Return type

Return a PeriodicCallback object with start and stop methods.

app(notebook_url='localhost:8888', port=0)

Displays a bokeh server app inline in the notebook.

Parameters
  • notebook_url (str) – URL to the notebook server

  • port (int (optional, default=0)) – Allows specifying a specific port

classmethod applies(obj)[source]

Given the object return a boolean indicating whether the Pane can render the object. If the priority of the pane is set to None, this method may also be used to define a priority depending on the object being rendered.

clone(object=None, **params)

Makes a copy of the Pane sharing the same parameters.

Parameters

params (Keyword arguments override the parameters on the clone.) –

Returns

Return type

Cloned Pane object

controls(parameters=[], jslink=True)

Creates a set of widgets which allow manipulating the parameters on this instance. By default all parameters which support linking are exposed, but an explicit list of parameters can be provided.

Parameters
  • parameters (list(str)) – An explicit list of parameters to return controls for.

  • jslink (bool) – Whether to use jslinks instead of Python based links. This does not allow using all types of parameters.

Returns

Return type

A layout of the controls

default_layout

alias of panel.layout.Column

embed(max_states=1000, max_opts=3, json=False, save_path='./', load_path=None, progress=True)

Renders a static version of a panel in a notebook by evaluating the set of states defined by the widgets in the model. Note this will only work well for simple apps with a relatively small state space.

Parameters
  • max_states (int) – The maximum number of states to embed

  • max_opts (int) – The maximum number of states for a single widget

  • json (boolean (default=True)) – Whether to export the data to json files

  • save_path (str (default='./')) – The path to save json files to

  • load_path (str (default=None)) – The path or URL the json files will be loaded from.

  • progress (boolean (default=False)) – Whether to report progress

expand_layout

alias of panel.layout.Column

classmethod get_pane_type(obj, **kwargs)

Returns the applicable Pane type given an object by resolving the precedence of all types whose applies method declares that the object is supported.

Parameters

(object) (obj) –

Returns

Return type

The applicable Pane type with the highest precedence.

get_root(doc=None, comm=None)[source]

Returns the root model and applies pre-processing hooks

Parameters
  • doc (bokeh.Document) – Bokeh document the bokeh model will be attached to.

  • comm (pyviz_comms.Comm) – Optional pyviz_comms when working in notebook

Returns

Return type

Returns the bokeh model corresponding to this panel object

jscallback(args={}, **callbacks)

Allows defining a JS callback to be triggered when a property changes on the source object. The keyword arguments define the properties that trigger a callback and the JS code that gets executed.

Parameters
  • args (dict) – A mapping of objects to make available to the JS callback

  • **callbacks (dict) – A mapping between properties on the source model and the code to execute when that property changes

Returns

callback – The Callback which can be used to disable the callback.

Return type

Callback

Links properties on the source object to those on the target object in JS code. Supports two modes, either specify a mapping between the source and target model properties as keywords or provide a dictionary of JS code snippets which maps from the source parameter to a JS code snippet which is executed when the property changes.

Parameters
  • target (HoloViews object or bokeh Model or panel Viewable) – The target to link the value to.

  • code (dict) – Custom code which will be executed when the widget value changes.

  • bidirectional (boolean) – Whether to link source and target bi-directionally

  • **links (dict) – A mapping between properties on the source model and the target model property to link it to.

Returns

link – The GenericLink which can be used unlink the widget and the target model.

Return type

GenericLink

Links the parameters on this object to attributes on another object in Python. Supports two modes, either specify a mapping between the source and target object parameters as keywords or provide a dictionary of callbacks which maps from the source parameter to a callback which is triggered when the parameter changes.

Parameters
  • target (object) – The target object of the link.

  • callbacks (dict) – Maps from a parameter in the source object to a callback.

  • **links (dict) – Maps between parameters on this object to the parameters on the supplied object.

pprint()

Prints a compositional repr of the class.

save(filename, title=None, resources=None, template=None, template_variables=None, embed=False, max_states=1000, max_opts=3, embed_json=False, json_prefix='', save_path='./', load_path=None)

Saves Panel objects to file.

Parameters
  • filename (string or file-like object) – Filename to save the plot to

  • title (string) – Optional title for the plot

  • resources (bokeh resources) – One of the valid bokeh.resources (e.g. CDN or INLINE)

  • template – passed to underlying io.save

  • template_variables – passed to underlying io.save

  • embed (bool) – Whether the state space should be embedded in the saved file.

  • max_states (int) – The maximum number of states to embed

  • max_opts (int) – The maximum number of states for a single widget

  • embed_json (boolean (default=True)) – Whether to export the data to json files

  • json_prefix (str (default='')) – Prefix for the auto-generated json directory

  • save_path (str (default='./')) – The path to save json files to

  • load_path (str (default=None)) – The path or URL the json files will be loaded from.

select(selector=None)[source]

Iterates over the Viewable and any potential children in the applying the Selector.

Parameters

selector (type or callable or None) – The selector allows selecting a subset of Viewables by declaring a type or callable function to filter by.

Returns

viewables

Return type

list(Viewable)

servable(title=None)

Serves the object if in a panel serve context and returns the Panel object to allow it to display itself in a notebook context.

Parameters

title (str) – A string title to give the Document (if served as an app)

Returns

Return type

The Panel object itself

server_doc(doc=None, title=None)

Returns a serveable bokeh Document with the panel attached

Parameters
  • doc (bokeh.Document (optional)) – The bokeh Document to attach the panel to as a root, defaults to bokeh.io.curdoc()

  • title (str) – A string title to give the Document

Returns

doc – The bokeh document the panel was attached to

Return type

bokeh.Document

show(title=None, port=0, websocket_origin=None, threaded=False, verbose=True, open=True, **kwargs)

Starts a Bokeh server and displays the Viewable in a new tab.

Parameters
  • port (int (optional, default=0)) – Allows specifying a specific port

  • websocket_origin (str or list(str) (optional)) – A list of hosts that can connect to the websocket. This is typically required when embedding a server app in an external web site. If None, “localhost” is used.

  • threaded (boolean (optional, default=False)) – Whether to launch the Server on a separate thread, allowing interactive use.

  • title (str) – A string title to give the Document (if served as an app)

  • verbose (boolean (optional, default=True)) – Whether to print the address and port

  • open (boolean (optional, default=True)) – Whether to open the server in a new browser tab

Returns

server – Returns the Bokeh server instance or the thread the server was launched on (if threaded=True)

Return type

bokeh.server.Server or threading.Thread

widget(p_name)[source]

Get widget for param_name

class panel.param.ParamFunction(object=None, **params)[source]

Bases: panel.param.ParamMethod

ParamFunction panes wrap functions decorated with the param.depends decorator and rerenders the output when any of the function’s dependencies change. This allows building reactive components into a Panel which depend on other parameters, e.g. tying the value of a widget to some other output.

Parameters inherited from:

panel.viewable.Layoutable: align, aspect_ratio, background, css_classes, width, height, min_width, min_height, max_width, max_height, margin, width_policy, height_policy, sizing_mode

panel.pane.base.PaneBase: default_layout, object

add_periodic_callback(callback, period=500, count=None, timeout=None, start=True)

Schedules a periodic callback to be run at an interval set by the period. Returns a PeriodicCallback object with the option to stop and start the callback.

Parameters
  • callback (callable) – Callable function to be executed at periodic interval.

  • period (int) – Interval in milliseconds at which callback will be executed.

  • count (int) – Maximum number of times callback will be invoked.

  • timeout (int) – Timeout in seconds when the callback should be stopped.

  • start (boolean (default=True)) – Whether to start callback immediately.

Returns

Return type

Return a PeriodicCallback object with start and stop methods.

app(notebook_url='localhost:8888', port=0)

Displays a bokeh server app inline in the notebook.

Parameters
  • notebook_url (str) – URL to the notebook server

  • port (int (optional, default=0)) – Allows specifying a specific port

classmethod applies(obj)[source]

Given the object return a boolean indicating whether the Pane can render the object. If the priority of the pane is set to None, this method may also be used to define a priority depending on the object being rendered.

clone(object=None, **params)

Makes a copy of the Pane sharing the same parameters.

Parameters

params (Keyword arguments override the parameters on the clone.) –

Returns

Return type

Cloned Pane object

controls(parameters=[], jslink=True)

Creates a set of widgets which allow manipulating the parameters on this instance. By default all parameters which support linking are exposed, but an explicit list of parameters can be provided.

Parameters
  • parameters (list(str)) – An explicit list of parameters to return controls for.

  • jslink (bool) – Whether to use jslinks instead of Python based links. This does not allow using all types of parameters.

Returns

Return type

A layout of the controls

default_layout

alias of panel.layout.Row

embed(max_states=1000, max_opts=3, json=False, save_path='./', load_path=None, progress=True)

Renders a static version of a panel in a notebook by evaluating the set of states defined by the widgets in the model. Note this will only work well for simple apps with a relatively small state space.

Parameters
  • max_states (int) – The maximum number of states to embed

  • max_opts (int) – The maximum number of states for a single widget

  • json (boolean (default=True)) – Whether to export the data to json files

  • save_path (str (default='./')) – The path to save json files to

  • load_path (str (default=None)) – The path or URL the json files will be loaded from.

  • progress (boolean (default=False)) – Whether to report progress

classmethod get_pane_type(obj, **kwargs)

Returns the applicable Pane type given an object by resolving the precedence of all types whose applies method declares that the object is supported.

Parameters

(object) (obj) –

Returns

Return type

The applicable Pane type with the highest precedence.

get_root(doc=None, comm=None)

Returns the root model and applies pre-processing hooks

Parameters
  • doc (bokeh.Document) – Bokeh document the bokeh model will be attached to.

  • comm (pyviz_comms.Comm) – Optional pyviz_comms when working in notebook

Returns

Return type

Returns the bokeh model corresponding to this panel object

jscallback(args={}, **callbacks)

Allows defining a JS callback to be triggered when a property changes on the source object. The keyword arguments define the properties that trigger a callback and the JS code that gets executed.

Parameters
  • args (dict) – A mapping of objects to make available to the JS callback

  • **callbacks (dict) – A mapping between properties on the source model and the code to execute when that property changes

Returns

callback – The Callback which can be used to disable the callback.

Return type

Callback

Links properties on the source object to those on the target object in JS code. Supports two modes, either specify a mapping between the source and target model properties as keywords or provide a dictionary of JS code snippets which maps from the source parameter to a JS code snippet which is executed when the property changes.

Parameters
  • target (HoloViews object or bokeh Model or panel Viewable) – The target to link the value to.

  • code (dict) – Custom code which will be executed when the widget value changes.

  • bidirectional (boolean) – Whether to link source and target bi-directionally

  • **links (dict) – A mapping between properties on the source model and the target model property to link it to.

Returns

link – The GenericLink which can be used unlink the widget and the target model.

Return type

GenericLink

Links the parameters on this object to attributes on another object in Python. Supports two modes, either specify a mapping between the source and target object parameters as keywords or provide a dictionary of callbacks which maps from the source parameter to a callback which is triggered when the parameter changes.

Parameters
  • target (object) – The target object of the link.

  • callbacks (dict) – Maps from a parameter in the source object to a callback.

  • **links (dict) – Maps between parameters on this object to the parameters on the supplied object.

pprint()

Prints a compositional repr of the class.

save(filename, title=None, resources=None, template=None, template_variables=None, embed=False, max_states=1000, max_opts=3, embed_json=False, json_prefix='', save_path='./', load_path=None)

Saves Panel objects to file.

Parameters
  • filename (string or file-like object) – Filename to save the plot to

  • title (string) – Optional title for the plot

  • resources (bokeh resources) – One of the valid bokeh.resources (e.g. CDN or INLINE)

  • template – passed to underlying io.save

  • template_variables – passed to underlying io.save

  • embed (bool) – Whether the state space should be embedded in the saved file.

  • max_states (int) – The maximum number of states to embed

  • max_opts (int) – The maximum number of states for a single widget

  • embed_json (boolean (default=True)) – Whether to export the data to json files

  • json_prefix (str (default='')) – Prefix for the auto-generated json directory

  • save_path (str (default='./')) – The path to save json files to

  • load_path (str (default=None)) – The path or URL the json files will be loaded from.

select(selector=None)

Iterates over the Viewable and any potential children in the applying the Selector.

Parameters

selector (type or callable or None) – The selector allows selecting a subset of Viewables by declaring a type or callable function to filter by.

Returns

viewables

Return type

list(Viewable)

servable(title=None)

Serves the object if in a panel serve context and returns the Panel object to allow it to display itself in a notebook context.

Parameters

title (str) – A string title to give the Document (if served as an app)

Returns

Return type

The Panel object itself

server_doc(doc=None, title=None)

Returns a serveable bokeh Document with the panel attached

Parameters
  • doc (bokeh.Document (optional)) – The bokeh Document to attach the panel to as a root, defaults to bokeh.io.curdoc()

  • title (str) – A string title to give the Document

Returns

doc – The bokeh document the panel was attached to

Return type

bokeh.Document

show(title=None, port=0, websocket_origin=None, threaded=False, verbose=True, open=True, **kwargs)

Starts a Bokeh server and displays the Viewable in a new tab.

Parameters
  • port (int (optional, default=0)) – Allows specifying a specific port

  • websocket_origin (str or list(str) (optional)) – A list of hosts that can connect to the websocket. This is typically required when embedding a server app in an external web site. If None, “localhost” is used.

  • threaded (boolean (optional, default=False)) – Whether to launch the Server on a separate thread, allowing interactive use.

  • title (str) – A string title to give the Document (if served as an app)

  • verbose (boolean (optional, default=True)) – Whether to print the address and port

  • open (boolean (optional, default=True)) – Whether to open the server in a new browser tab

Returns

server – Returns the Bokeh server instance or the thread the server was launched on (if threaded=True)

Return type

bokeh.server.Server or threading.Thread

class panel.param.ParamMethod(object=None, **params)[source]

Bases: panel.pane.base.ReplacementPane

ParamMethod panes wrap methods on parameterized classes and rerenders the plot when any of the method’s parameters change. By default ParamMethod will watch all parameters on the class owning the method or can be restricted to certain parameters by annotating the method using the param.depends decorator. The method may return any object which itself can be rendered as a Pane.

Parameters inherited from:

panel.viewable.Layoutable: align, aspect_ratio, background, css_classes, width, height, min_width, min_height, max_width, max_height, margin, width_policy, height_policy, sizing_mode

panel.pane.base.PaneBase: default_layout, object

add_periodic_callback(callback, period=500, count=None, timeout=None, start=True)

Schedules a periodic callback to be run at an interval set by the period. Returns a PeriodicCallback object with the option to stop and start the callback.

Parameters
  • callback (callable) – Callable function to be executed at periodic interval.

  • period (int) – Interval in milliseconds at which callback will be executed.

  • count (int) – Maximum number of times callback will be invoked.

  • timeout (int) – Timeout in seconds when the callback should be stopped.

  • start (boolean (default=True)) – Whether to start callback immediately.

Returns

Return type

Return a PeriodicCallback object with start and stop methods.

app(notebook_url='localhost:8888', port=0)

Displays a bokeh server app inline in the notebook.

Parameters
  • notebook_url (str) – URL to the notebook server

  • port (int (optional, default=0)) – Allows specifying a specific port

classmethod applies(obj)[source]

Given the object return a boolean indicating whether the Pane can render the object. If the priority of the pane is set to None, this method may also be used to define a priority depending on the object being rendered.

clone(object=None, **params)

Makes a copy of the Pane sharing the same parameters.

Parameters

params (Keyword arguments override the parameters on the clone.) –

Returns

Return type

Cloned Pane object

controls(parameters=[], jslink=True)

Creates a set of widgets which allow manipulating the parameters on this instance. By default all parameters which support linking are exposed, but an explicit list of parameters can be provided.

Parameters
  • parameters (list(str)) – An explicit list of parameters to return controls for.

  • jslink (bool) – Whether to use jslinks instead of Python based links. This does not allow using all types of parameters.

Returns

Return type

A layout of the controls

default_layout

alias of panel.layout.Row

embed(max_states=1000, max_opts=3, json=False, save_path='./', load_path=None, progress=True)

Renders a static version of a panel in a notebook by evaluating the set of states defined by the widgets in the model. Note this will only work well for simple apps with a relatively small state space.

Parameters
  • max_states (int) – The maximum number of states to embed

  • max_opts (int) – The maximum number of states for a single widget

  • json (boolean (default=True)) – Whether to export the data to json files

  • save_path (str (default='./')) – The path to save json files to

  • load_path (str (default=None)) – The path or URL the json files will be loaded from.

  • progress (boolean (default=False)) – Whether to report progress

classmethod get_pane_type(obj, **kwargs)

Returns the applicable Pane type given an object by resolving the precedence of all types whose applies method declares that the object is supported.

Parameters

(object) (obj) –

Returns

Return type

The applicable Pane type with the highest precedence.

get_root(doc=None, comm=None)

Returns the root model and applies pre-processing hooks

Parameters
  • doc (bokeh.Document) – Bokeh document the bokeh model will be attached to.

  • comm (pyviz_comms.Comm) – Optional pyviz_comms when working in notebook

Returns

Return type

Returns the bokeh model corresponding to this panel object

jscallback(args={}, **callbacks)

Allows defining a JS callback to be triggered when a property changes on the source object. The keyword arguments define the properties that trigger a callback and the JS code that gets executed.

Parameters
  • args (dict) – A mapping of objects to make available to the JS callback

  • **callbacks (dict) – A mapping between properties on the source model and the code to execute when that property changes

Returns

callback – The Callback which can be used to disable the callback.

Return type

Callback

Links properties on the source object to those on the target object in JS code. Supports two modes, either specify a mapping between the source and target model properties as keywords or provide a dictionary of JS code snippets which maps from the source parameter to a JS code snippet which is executed when the property changes.

Parameters
  • target (HoloViews object or bokeh Model or panel Viewable) – The target to link the value to.

  • code (dict) – Custom code which will be executed when the widget value changes.

  • bidirectional (boolean) – Whether to link source and target bi-directionally

  • **links (dict) – A mapping between properties on the source model and the target model property to link it to.

Returns

link – The GenericLink which can be used unlink the widget and the target model.

Return type

GenericLink

Links the parameters on this object to attributes on another object in Python. Supports two modes, either specify a mapping between the source and target object parameters as keywords or provide a dictionary of callbacks which maps from the source parameter to a callback which is triggered when the parameter changes.

Parameters
  • target (object) – The target object of the link.

  • callbacks (dict) – Maps from a parameter in the source object to a callback.

  • **links (dict) – Maps between parameters on this object to the parameters on the supplied object.

pprint()

Prints a compositional repr of the class.

save(filename, title=None, resources=None, template=None, template_variables=None, embed=False, max_states=1000, max_opts=3, embed_json=False, json_prefix='', save_path='./', load_path=None)

Saves Panel objects to file.

Parameters
  • filename (string or file-like object) – Filename to save the plot to

  • title (string) – Optional title for the plot

  • resources (bokeh resources) – One of the valid bokeh.resources (e.g. CDN or INLINE)

  • template – passed to underlying io.save

  • template_variables – passed to underlying io.save

  • embed (bool) – Whether the state space should be embedded in the saved file.

  • max_states (int) – The maximum number of states to embed

  • max_opts (int) – The maximum number of states for a single widget

  • embed_json (boolean (default=True)) – Whether to export the data to json files

  • json_prefix (str (default='')) – Prefix for the auto-generated json directory

  • save_path (str (default='./')) – The path to save json files to

  • load_path (str (default=None)) – The path or URL the json files will be loaded from.

select(selector=None)

Iterates over the Viewable and any potential children in the applying the Selector.

Parameters

selector (type or callable or None) – The selector allows selecting a subset of Viewables by declaring a type or callable function to filter by.

Returns

viewables

Return type

list(Viewable)

servable(title=None)

Serves the object if in a panel serve context and returns the Panel object to allow it to display itself in a notebook context.

Parameters

title (str) – A string title to give the Document (if served as an app)

Returns

Return type

The Panel object itself

server_doc(doc=None, title=None)

Returns a serveable bokeh Document with the panel attached

Parameters
  • doc (bokeh.Document (optional)) – The bokeh Document to attach the panel to as a root, defaults to bokeh.io.curdoc()

  • title (str) – A string title to give the Document

Returns

doc – The bokeh document the panel was attached to

Return type

bokeh.Document

show(title=None, port=0, websocket_origin=None, threaded=False, verbose=True, open=True, **kwargs)

Starts a Bokeh server and displays the Viewable in a new tab.

Parameters
  • port (int (optional, default=0)) – Allows specifying a specific port

  • websocket_origin (str or list(str) (optional)) – A list of hosts that can connect to the websocket. This is typically required when embedding a server app in an external web site. If None, “localhost” is used.

  • threaded (boolean (optional, default=False)) – Whether to launch the Server on a separate thread, allowing interactive use.

  • title (str) – A string title to give the Document (if served as an app)

  • verbose (boolean (optional, default=True)) – Whether to print the address and port

  • open (boolean (optional, default=True)) – Whether to open the server in a new browser tab

Returns

server – Returns the Bokeh server instance or the thread the server was launched on (if threaded=True)

Return type

bokeh.server.Server or threading.Thread

panel.param.SingleFileSelector(pobj)[source]

Determines whether to use a TextInput or Select widget for FileSelector