AltairWidget API

Bases: AnyWidget

Flicker-free Altair chart widget.

Wraps an Altair chart and uses the Vega View API to update data in-place when only the data portion of the spec changes, avoiding full DOM rebuilds.

The widget should be created once and then updated via the chart setter from a reactive cell. This keeps the DOM element stable and allows the JavaScript side to detect data-only changes and apply them smoothly.

Examples:

import altair as alt
import pandas as pd
from wigglystuff import AltairWidget

df = pd.DataFrame({"x": [1, 2, 3], "y": [4, 5, 6]})
chart = alt.Chart(df).mark_point().encode(x="x", y="y")
widget = AltairWidget(chart)
widget

Create an AltairWidget.

Parameters:

Name	Type	Description	Default
chart	Any	An Altair chart object or a Vega-Lite spec dict. If None, the widget starts empty and can be populated later via the chart setter.	None
width	int	Container width in pixels.	600
height	int	Container height in pixels.	400
**kwargs	Any	Forwarded to anywidget.AnyWidget.	{}

Source code in wigglystuff/altair_widget.py

def __init__(
    self,
    chart: Any = None,
    *,
    width: int = 600,
    height: int = 400,
    **kwargs: Any,
) -> None:
    """Create an AltairWidget.

    Args:
        chart: An Altair chart object or a Vega-Lite spec dict. If ``None``,
            the widget starts empty and can be populated later via the
            ``chart`` setter.
        width: Container width in pixels.
        height: Container height in pixels.
        **kwargs: Forwarded to ``anywidget.AnyWidget``.
    """
    spec = {}
    if chart is not None:
        spec = self._chart_to_spec(chart)
    super().__init__(
        spec=spec,
        width=width,
        height=height,
        **kwargs,
    )

chart property writable

chart

Write-only convenience property. Read widget.spec instead.

Synced traitlets

Traitlet	Type	Notes
spec	dict	Full Vega-Lite spec (from chart.to_dict()).
width	int	Container width in pixels.
height	int	Container height in pixels.