JupyterLab Widgets Extension

3.0.16 · active · verified Sat Mar 28

`jupyterlab-widgets` is the JupyterLab frontend extension that provides the necessary framework for rendering interactive `ipywidgets` within JupyterLab notebooks and interfaces. It enables the rich interactive experiences defined by the core `ipywidgets` Python library. As of version 3.0.16, this extension is compatible with JupyterLab 3 and 4, and for many modern setups, it is automatically handled or included when `ipywidgets` is installed.

Warnings

gotcha It is important to distinguish between `jupyterlab-widgets` and `ipywidgets`. `ipywidgets` is the core Python library for defining and creating interactive widgets, while `jupyterlab-widgets` is the JupyterLab frontend extension responsible for rendering these widgets. Users primarily interact with `ipywidgets` in their Python code.
Fix: When developing, import widget classes and functions from `ipywidgets`. Ensure both `ipywidgets` and `jupyterlab-widgets` are installed for proper rendering in JupyterLab.
breaking JupyterLab version compatibility for the `jupyterlab-widgets` extension has historically required specific installation steps. For JupyterLab 1 or 2, manual `jupyter labextension install` was often necessary. JupyterLab 3.0+ and `ipywidgets>=7.6.0` typically handle the extension automatically, but compatibility issues can still arise, especially with major JupyterLab upgrades (e.g., to JupyterLab 4).
Fix: For JupyterLab 3.0 and newer, `pip install ipywidgets` is usually sufficient. If issues persist, ensure `jupyterlab-widgets` is also explicitly installed via `pip install jupyterlab-widgets` and check `jupyter labextension list` for its status. For older JupyterLab versions, consult the `jupyterlab-widgets` PyPI page for specific `jupyter labextension install` commands.
gotcha If JupyterLab and your Python kernel (with `ipywidgets`) are installed in separate virtual environments (e.g., using different Conda environments), `jupyterlab-widgets` must be installed in the environment where JupyterLab is running, and `ipywidgets` must be installed in each kernel's environment that will use widgets.
Fix: Ensure `jupyterlab-widgets` is present in the JupyterLab environment and `ipywidgets` in the kernel environment. Use `conda list` or `pip list` in both environments to verify.

Install

pip install jupyterlab-widgets JupyterLab Widget Extension
pip install ipywidgets Core Widget Library (commonly sufficient for Lab 3+)

Imports

Button
```
from ipywidgets import Button, IntSlider, interact
```
The `jupyterlab-widgets` package is a JupyterLab frontend extension. User-facing Python imports for creating and using interactive widgets are provided by the `ipywidgets` library, which this extension enables in JupyterLab.
display
```
from IPython.display import display
```
While `ipywidgets` creates the widget objects, `IPython.display.display` is often used to explicitly render widgets in contexts where they might not automatically show up (e.g., when not the last expression in a cell).

Quickstart

This quickstart demonstrates how to create and display a simple integer slider using `ipywidgets`, which `jupyterlab-widgets` enables in JupyterLab. It also shows the `interact` function for automatically creating widgets for function arguments.

from ipywidgets import IntSlider, interact
from IPython.display import display

def f(x):
    print(x)

# Create a slider widget
slider = IntSlider(min=0, max=100, step=1, description='Value:')
display(slider)

# Or use interact for quick interactive functions
interact(f, x=10);

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