Interactive Jupyter Widgets not working in Jupyter Lab

Question

I noticed that interactive widgets are not working in my Jupyter Lab notebooks.

The following code should produce an interactive slider but doesn\'t:

Answer 1

You need to install widget extension

pip install ipywidgets
jupyter nbextension enable --py widgetsnbextension --sys-prefix

Answer 2

Per the docs:

To install the JupyterLab extension you also need to run the command below in a terminal which requires that you have nodejs installed.

jupyter labextension install @jupyter-widgets/jupyterlab-manager

I think it's the latter nodejs requirement that you are missing e.g. with Conda, first run:

conda install nodejs