panel.param module#

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

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

Bases: Pane

Param panes render a Parameterized class into a set of interactive widgets that are dynamically linked to the parameter values of the class.

Reference: https://panel.holoviz.org/reference/panes/Param.html

Example:

>>> import param
>>> import panel as pn
>>> pn.extension()

>>> class App(param.Parameterized):
>>>     some_text = param.String(default="Hello")
>>>     some_float = param.Number(default=1, bounds=(0, 10), step=0.1)
>>>     some_boolean = param.Boolean(default=True)

>>> app = App()

>>> pn.Param(app, parameters=["some_text", "some_float"], show_name=False).servable()

Attributes:

widgets

Methods

`applies`(obj)	Returns boolean or float indicating whether the Pane can render the object.
`get_root`([doc, comm, preprocess])	Returns the root model and applies pre-processing hooks
`select`([selector])	Iterates over the Viewable and any potential children in the applying the Selector.
`widget`(p_name)	Get widget for param_name

widget_type

Parameter Definitions

Parameters inherited from:

panel.viewable.Layoutable: align, aspect_ratio, css_classes, design, min_width, min_height, max_width, max_height, styles, stylesheets, tags, width_policy, height_policy, sizing_mode, visible

panel.viewable.Viewable: loading

panel.pane.base.PaneBase: margin

height = Integer(allow_None=True, bounds=(0, None), inclusive_bounds=(True, True), label='Height'): Height of widgetbox the parameter widgets are displayed in.
width = Integer(allow_None=True, bounds=(0, None), inclusive_bounds=(True, True), label='Width'): Width of widgetbox the parameter widgets are displayed in.
default_layout = ClassSelector(class_=<class 'panel.layout.base.Panel'>, default=<class 'panel.layout.base.Column'>, label='Default layout'): Defines the layout the model(s) returned by the pane will be placed in.
object = Parameter(allow_None=True, label='Object'): The object being wrapped, which will be converted to a Bokeh model.
display_threshold = Number(default=0, inclusive_bounds=(True, True), label='Display threshold'): Parameters with precedence below this value are not displayed.
default_precedence = Number(default=1e-08, inclusive_bounds=(True, True), label='Default precedence'): 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 = Boolean(default=False, label='Expand'): Whether parameterized subobjects are expanded or collapsed on instantiation.
expand_button = Boolean(allow_None=True, label='Expand button'): Whether to add buttons to expand and collapse sub-objects.
expand_layout = Parameter(default=<class 'panel.layout.base.Column'>, label='Expand layout'): Layout to expand sub-objects into.
hide_constant = Boolean(default=False, label='Hide constant'): Whether to hide widgets of constant parameters.
initializer = Callable(allow_None=True, label='Initializer'): User-supplied function that will be called on initialization, usually to update the default Parameter values of the underlying parameterized object.
parameters = List(allow_None=True, bounds=(0, None), default=[], label='Parameters'): If set this serves as a allowlist of parameters to display on the supplied Parameterized object.
show_labels = Boolean(default=True, label='Show labels'): Whether to show labels for each widget
show_name = Boolean(default=True, label='Show name'): Whether to show the parameterized object’s name
sort = ClassSelector(class_=(<class 'bool'>, <class 'collections.abc.Callable'>), default=False, label='Sort'): If True the widgets will be sorted alphabetically by label. If a callable is provided it will be used to sort the Parameters, for example lambda x: x[1].label[::-1] will sort by the reversed label.
widgets = Dict(allow_None=True, class_=<class 'dict'>, label='Widgets'): Dictionary of widget overrides, mapping from parameter name to widget class.

classmethod applies(obj: Any) → float | bool | None[source]#

Returns boolean or float 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 float priority depending on the object being rendered.

default_layout[source]#: alias of Column

expand_layout[source]#: alias of Column

get_root(doc: Document | None = None, comm: Comm | None = None, preprocess: bool = True) → Model[source]#

Returns the root model and applies pre-processing hooks

Parameters:

doc: bokeh.document.Document: Optional Bokeh document the bokeh model will be attached to.
comm: pyviz_comms.Comm: Optional pyviz_comms when working in notebook
preprocess: bool (default=True): Whether to run preprocessing hooks

Returns:

Returns the bokeh model corresponding to this panel object

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: list(Viewable)

widget(p_name)[source]#: Get widget for param_name

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

Bases: ParamRef

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.

Methods

applies(obj, **kwargs)

Returns boolean or float indicating whether the Pane can render the object.

eval

Parameter Definitions

Parameters inherited from:

panel.viewable.Layoutable: align, aspect_ratio, css_classes, design, height, min_width, min_height, max_width, max_height, styles, stylesheets, tags, width, width_policy, height_policy, sizing_mode, visible

panel.viewable.Viewable: loading

panel.pane.base.PaneBase: margin, default_layout

panel.pane.base.ReplacementPane: object, inplace, _pane

panel.param.ParamRef: defer_load, generator_mode, lazy, loading_indicator

classmethod applies(obj: Any, **kwargs) → float | bool | None[source]#

Returns boolean or float 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 float priority depending on the object being rendered.

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

Bases: ParamRef

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.

Methods

applies(obj)

Returns boolean or float indicating whether the Pane can render the object.

eval

Parameter Definitions

Parameters inherited from:

panel.viewable.Layoutable: align, aspect_ratio, css_classes, design, height, min_width, min_height, max_width, max_height, styles, stylesheets, tags, width, width_policy, height_policy, sizing_mode, visible

panel.viewable.Viewable: loading

panel.pane.base.PaneBase: margin, default_layout

panel.pane.base.ReplacementPane: object, inplace, _pane

panel.param.ParamRef: defer_load, generator_mode, lazy, loading_indicator

classmethod applies(obj: Any) → float | bool | None[source]#

Returns boolean or float 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 float priority depending on the object being rendered.

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

Bases: Pane

ReactiveExpr generates a UI for param.rx objects by rendering the widgets and outputs.

Attributes:

widgets

Methods

applies(object)

Returns boolean or float indicating whether the Pane can render the object.

Parameter Definitions

Parameters inherited from:

panel.viewable.Layoutable: align, aspect_ratio, css_classes, design, height, min_width, min_height, max_width, max_height, styles, stylesheets, tags, width, width_policy, height_policy, sizing_mode, visible

panel.viewable.Viewable: loading

panel.pane.base.PaneBase: margin, default_layout

object = Parameter(allow_None=True, label='Object'): The object being wrapped, which will be converted to a Bokeh model.
center = Boolean(default=False, label='Center'): Whether to center the output.
show_widgets = Boolean(default=True, label='Show widgets'): Whether to display the widget inputs.
widget_layout = Selector(constant=True, default=<class 'panel.layout.base.WidgetBox'>, label='Widget layout', names={}, objects=[<class 'panel.layout.base.WidgetBox'>, <class 'panel.layout.base.Row'>, <class 'panel.layout.base.Column'>]): The layout object to display the widgets in.
widget_location = Selector(default='left_top', label='Widget location', names={}, objects=['left', 'right', 'top', 'bottom', 'top_left', 'top_right', 'bottom_left', 'bottom_right', 'left_top', 'right_top', 'right_bottom']): The location of the widgets relative to the output of the reactive expression.

classmethod applies(object)[source]#

Returns boolean or float 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 float priority depending on the object being rendered.

widget_layout[source]#: alias of WidgetBox

panel.param.set_values(*parameterizeds, **param_values)[source]#

Temporarily sets parameter values to the specified values on all supplied Parameterized objects.

Parameters:

parameterizeds: tuple(param.Parameterized): Any number of parameterized objects.
param_values: dict: A dictionary of parameter names and temporary values.