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Views

lumen.views

base

The View classes render the data returned by a Pipeline as a Panel object.

DOWNLOAD_FORMATS = ['csv', 'xlsx', 'json', 'parquet'] module-attribute

AltairView

Bases: View

AltairView provides a declarative way to render Altair charts.

chart = param.Dict(default={}, doc='Keyword argument for Chart.') class-attribute instance-attribute
encode = param.Dict(default={}, doc='Keyword arguments for encode.') class-attribute instance-attribute
mark = param.Dict(default={}, doc='Keyword arguments for mark.') class-attribute instance-attribute
marker = param.Selector(default='line', objects=['area', 'bar', 'boxplot', 'circle', 'errorband', 'errorbar', 'geoshape', 'image', 'line', 'point', 'rect', 'rule', 'square', 'text', 'tick', 'trail']) class-attribute instance-attribute
project = param.Dict(doc='Keyword arguments for project.') class-attribute instance-attribute
properties = param.Dict(doc='Keyword arguments for properties.') class-attribute instance-attribute
transform = param.Dict(doc="\n Keyword arguments for transforms, nested by the type of\n transform, e.g. {'bin': {'as_': 'binned', 'field': 'x'}}.") class-attribute instance-attribute
view_type = 'altair' class-attribute instance-attribute
x = param.Selector(doc='The column to render on the x-axis.') class-attribute instance-attribute
y = param.Selector(doc='The column to render on the y-axis.') class-attribute instance-attribute
get_panel()

DownloadView

Bases: View

DownloadView renders a button that allows downloading data as CSV, Excel, and parquet files.

filename = param.String(default='data', doc='\n Filename of the downloaded file.') class-attribute instance-attribute
format = param.Selector(default=None, objects=DOWNLOAD_FORMATS, doc='\n The format to download the data in.') class-attribute instance-attribute
icon = param.String(default='file-spreadsheet', doc='\n Icon to show on the button.') class-attribute instance-attribute
kwargs = param.Dict(default={}, doc='\n Keyword arguments passed to the serialization function, e.g.\n data.to_csv(file_obj, **kwargs).') class-attribute instance-attribute
view_type = 'download' class-attribute instance-attribute
get_panel()

GraphicWalker

Bases: View

Renders the data using the GraphicWalker panel extension.

ignore_limit = param.Boolean(default=False, doc='\n Ignore any SQLLimit transform defined on the input pipeline.') class-attribute instance-attribute
kernel_computation = param.Boolean(default=False, doc="If True the computations will take place on the server or in the Jupyter kernel\n instead of the client to scale to larger datasets. Default is False. In Pyodide this will\n always be set to False. The 'chart' renderer will only work with client side rendering.") class-attribute instance-attribute
renderer = param.Selector(default='profiler', objects=['explorer', 'profiler', 'viewer', 'chart'], doc="How to display the data. One of 'explorer' (default), 'profiler,\n 'viewer' or 'chart'.") class-attribute instance-attribute
tab = param.Selector(default='data', objects=['data', 'vis'], doc="Set the active tab to 'data' or 'vis' (default). Only applicable for the 'explorer' renderer. Not bi-directionally synced with client.") class-attribute instance-attribute
view_type = 'graphic_walker' class-attribute instance-attribute
get_panel()

HoloViews

Bases: View

HoloViews renders the data as a HoloViews plot.

object = param.Parameter() class-attribute instance-attribute
streaming = param.Boolean(default=False, doc='\n Whether to stream new data to the plot or rerender the plot.') class-attribute instance-attribute
view_type = 'holoviews' class-attribute instance-attribute
from_spec(spec, source=None, filters=None, pipeline=None) classmethod
get_panel()
to_spec(context=None)

IndicatorView

Bases: View

IndicatorView renders the latest field value as a Panel Indicator.

indicator = param.Selector(objects=_INDICATORS, doc='\n The name of the panel Indicator type.') class-attribute instance-attribute
label = param.String(doc='\n A custom label to use for the Indicator.') class-attribute instance-attribute
view_type = 'indicator' class-attribute instance-attribute
get_panel()

Panel

Bases: View

Panel views provide a way to declaratively wrap a Panel component.

The Panel View is a very general purpose view that allows expressing arbitrary Panel objects as a specification. The Panel specification may be arbitrarily nested making it possible to specify entire layouts. Additionally the Panel specification also supports references, including standard source and variable references and a custom $data reference that inserts the current data of the View.

type: panel
  spec:
   type: panel.layout.Column
   objects:
     - type: pn.pane.Markdown
       object: '# My custom title'
     - type: pn.pane.DataFrame
       object: $data
object = Child() class-attribute instance-attribute
view_type = 'panel' class-attribute
from_spec(spec, source=None, filters=None, pipeline=None) classmethod
get_panel()
to_spec(context=None)

PerspectiveView

Bases: View

PerspectiveView renders data into a Perspective widget.

See https://panel.holoviz.org/reference/panes/Perspective.html for more details.

aggregates = param.Dict(None, allow_None=True, doc='\n How to aggregate. For example {x: "distinct count"}') class-attribute instance-attribute
column_pivots = param.ListSelector(None, allow_None=True, doc='\n A list of source columns to pivot by. For example ["x", "y"]') class-attribute instance-attribute
columns = param.ListSelector(default=None, allow_None=True, doc='\n A list of source columns to show as columns. For example ["x", "y"]') class-attribute instance-attribute
computed_columns = param.ListSelector(default=None, allow_None=True, doc='\n A list of computed columns. For example [""x"+"index""]') class-attribute instance-attribute
filters = param.List(default=None, allow_None=True, doc='\n How to filter. For example [["x", "<", 3],["y", "contains", "abc"]]') class-attribute instance-attribute
plugin = param.Selector(default=(_PerspectivePlugin.GRID.value), objects=(_PerspectivePlugin.options()), doc='\n The name of a plugin to display the data. For example hypergrid or d3_xy_scatter.') class-attribute instance-attribute
row_pivots = param.ListSelector(default=None, allow_None=True, doc='\n A list of source columns to group by. For example ["x", "y"]') class-attribute instance-attribute
selectable = param.Boolean(default=True, allow_None=True, doc='\n Whether items are selectable.') class-attribute instance-attribute
sort = param.List(default=None, doc='\n How to sort. For example[["x","desc"]]') class-attribute instance-attribute
theme = param.Selector(default='material', objects=_PERSPECTIVE_THEMES, doc='\n The style of the PerspectiveViewer. For example material-dark') class-attribute instance-attribute
view_type = 'perspective' class-attribute instance-attribute
get_panel()

StringView

Bases: View

StringView renders the latest value of the field as a HTML string.

font_size = param.String(default='24pt', doc='\n The font size of the rendered field value.') class-attribute instance-attribute
view_type = 'string' class-attribute
get_panel()

Table

Bases: View

Table renders data using the powerful Panel Tabulator component.

See https://panel.holoviz.org/reference/widgets/Tabulator.html

page_size = param.Integer(default=None, doc='\n Number of rows to render per page, if pagination is enabled.') class-attribute instance-attribute
view_type = 'table' class-attribute instance-attribute
get_panel()

VegaLiteView

Bases: View

VegaLite provides a declarative way to render vega-lite charts.

spec = param.Dict() class-attribute instance-attribute
view_type = 'vegalite' class-attribute instance-attribute
get_panel()

View

Bases: MultiTypeComponent, Viewer

View components provide a visual representation for the data returned by a :class:lumen.source.base.Source or :class:lumen.pipeline.Pipeline.

The View must return a Panel object or an object that can be rendered by Panel. The base class provides methods which query the the provided :class:lumen.pipeline.Pipeline.

Subclasses should use these methods to query the data and return a Viewable Panel object in the get_panel method.

control_panel property
controls = param.List(default=[], doc='\n Parameters that should be exposed as widgets in the UI.') class-attribute instance-attribute
download = param.ClassSelector(class_=Download, default=(Download()), doc='\n The download objects determines whether and how the source tables\n can be downloaded.') class-attribute instance-attribute
field = param.Selector(doc='The field being visualized.') class-attribute instance-attribute
kwargs = {k: v for k, v in (params.items()) if k not in self.param} instance-attribute
limit = param.Integer(default=None, bounds=(0, None), doc='\n Limits the number of rows that are rendered.') class-attribute instance-attribute
loading_indicator = param.Boolean(default=True, constant=True, doc='\n Whether to display a loading indicator on the View when the\n Pipeline is refreshing the data.') class-attribute instance-attribute
panel property
pipeline = param.ClassSelector(class_=Pipeline, doc='\n The data pipeline that drives the View.') class-attribute instance-attribute
rerender = param.Event(default=False, doc='\n An event that is triggered whenever the View requests a re-render.') class-attribute instance-attribute
selection_group = param.String(default=None, doc='\n Declares a selection group the plot is part of. This feature\n requires the separate HoloViews library.') class-attribute instance-attribute
title = param.String(default=None, doc='\n The title of the view.') class-attribute instance-attribute
view_type = None class-attribute
from_spec(spec, source=None, filters=None, pipeline=None) classmethod

Resolves a View specification given the schema of the Source it will be filtering on.

Parameters:

Name Type Description Default
spec dict[str, Any] | str

Specification declared as a dictionary of parameter values.

 required
source

The Source object containing the tables the View renders.

 None
filters

A list of Filter objects which provide query values for the Source.

 None
pipeline

The Lumen pipeline driving this View. Must not be supplied if the spec contains a pipeline definition or reference.

 None

Returns:

Type Description
The resolved View object.
get_data()

Queries the Source for the specified table applying any filters and transformations specified on the View. Unlike get_value this should be used when multiple return values are expected.

Returns:

Type Description
DataFrame

The queried table after filtering and transformations are applied.
get_panel()

Constructs and returns a Panel object which will represent a view of the queried table.

Returns:

Type Description
Viewable

A Panel Viewable object representing a current representation of the queried table.
get_value(field=None)

Queries the Source for the data associated with a particular field applying any filters and transformations specified on the View. Unlike get_data this method returns a single scalar value associated with the field and should therefore only be used if only a single.

Parameters:

Name Type Description Default
field str | None

The field from the table to return; if None uses field defined on the View.

 None

Returns:

Type Description
object

A single scalar value representing the current value of the queried field.
to_spec(context=None)

Exports the full specification to reconstruct this component.

Parameters:

Name Type Description Default
context dict[str, Any] | None

Context contains the specification of all previously serialized components, e.g. to allow resolving of references.

 None

Returns:

Type Description
Declarative specification of this component.
update(*events, invalidate_cache=True)

Triggers an update in the View.

Parameters:

Name Type Description Default
events Event

param events that may trigger an update.

 ()
invalidate_cache bool

Whether to clear the View's cache.

 True

YdataProfilingView

Bases: View

A View that renders a ydata_profiling ProfileReport.

view_type = 'ydata_profiling' class-attribute instance-attribute
get_panel()

hvOverlayView

Bases: View

hvOverlayView allows overlaying a list of layers consisting of hvPlotView components.

layers = param.List(item_type=hvPlotView) class-attribute instance-attribute
view_type = 'hv_overlay' class-attribute instance-attribute
get_panel()

hvPlotBaseView

Bases: View

by = param.ListSelector(doc='The column(s) to facet the plot by.') class-attribute instance-attribute
geo = param.Boolean(default=False, doc='Toggle True if the plot is on a geographic map.') class-attribute instance-attribute
groupby = param.ListSelector(doc='The column(s) to group by.') class-attribute instance-attribute
kind = param.Selector(default=None, doc="The kind of plot, e.g. 'scatter' or 'line'.", objects=['area', 'bar', 'barh', 'bivariate', 'box', 'contour', 'contourf', 'errorbars', 'hist', 'image', 'kde', 'labels', 'line', 'scatter', 'heatmap', 'hexbin', 'ohlc', 'points', 'step', 'violin']) class-attribute instance-attribute
x = param.Selector(doc='The column to render on the x-axis.') class-attribute instance-attribute
y = param.Selector(doc='The column to render on the y-axis.') class-attribute instance-attribute

hvPlotUIView

Bases: hvPlotBaseView

hvPlotUIView displays provides a component for exploring datasets interactively.

view_type = 'hvplot_ui' class-attribute instance-attribute
get_panel()

hvPlotView

Bases: hvPlotBaseView

hvPlotView renders the queried data as a bokeh plot generated with hvPlot.

hvPlot allows for a concise but powerful declaration of a plot via its simple API.

operations = param.List(item_type=(param.ParameterizedFunction), doc='\n Operations to apply to HoloViews plot.') class-attribute instance-attribute
opts = param.Dict(default={}, doc='HoloViews options to apply on the plot.') class-attribute instance-attribute
selection_expr = param.Parameter(doc='\n A selection expression caputirng the current selection applied\n on the plot.') class-attribute instance-attribute
streaming = param.Boolean(default=False, doc='\n Whether to stream new data to the plot or rerender the plot.') class-attribute instance-attribute
view_type = 'hvplot' class-attribute instance-attribute
get_panel()
get_plot(df)
update(*events, invalidate_cache=True)

Triggers an update in the View.

Parameters:

Name Type Description Default
events

param events that may trigger an update.

 ()
invalidate_cache bool

Whether to clear the View's cache.

 True