pyviz_comms

Offers a simple bidirectional communication architecture between Python and JavaScript, with support for Jupyter comms in both the classic notebook and Jupyterlab. Available for use by any PyViz tool, but currently primarily used by HoloViz tools.

There are two installable components in this repository: a Python component used by various HoloViz tools and an extension to enable Jupyterlab support. For JupyterLab 3.0 and above the extension is automatically bundled with the pyviz_comms Python package.

Installing the Jupyterlab extension

Jupyterlab users will need to install the Jupyterlab pyviz extension. Starting with JupyterLab 3.0 and above the extension will be automatically installed when installing pyviz_comms with pip using:

pip install pyviz_comms

or using conda with:

conda install -c pyviz pyviz_comms

For older versions of JupyterLab you must separately install:

jupyter labextension install @pyviz/jupyterlab_pyviz

Compatibility

The Holoviz libraries are generally version independent of JupyterLab and the jupyterlab_pyviz extension has been supported since holoviews 1.10.0 and the first release of pyviz_comms.

Our goal is that jupyterlab_pyviz minor releases (using the SemVer pattern) are made to follow JupyterLab minor release bumps and micro releases are for new jupyterlab_pyviz features or bug fix releases. We've been previously inconsistent with having the extension release minor version bumps track that of JupyterLab, so users seeking to find extension releases that are compatible with their JupyterLab installation may refer to the below table.

Compatible JupyterLab and jupyterlab_pyviz versions

JupyterLab	jupyterlab_pyviz
0.33.x	0.6.0
0.34.x	0.6.1-0.6.2
0.35.x	0.6.3-0.7.2
1.0.x	0.8.0
2.0.x	0.9.0-1.0.3
3.x	2.0
4.x	3.0

Developing the Jupyterlab extension

Note: You will need NodeJS to build the extension package.

The jlpm command is JupyterLab's pinned version of yarn that is installed with JupyterLab. You may use yarn or npm in lieu of jlpm below.

# Clone the repo to your local environment
# Change directory to the holoviz_jlab directory
# Install package in development mode
pip install -e .
# Link your development version of the extension with JupyterLab
jupyter labextension develop . --overwrite
# Rebuild extension Typescript source after making changes
jlpm run build

You can watch the source directory and run JupyterLab at the same time in different terminals to watch for changes in the extension's source and automatically rebuild the extension.

# Watch the source directory in one terminal, automatically rebuilding when needed
jlpm run watch
# Run JupyterLab in another terminal
jupyter lab

With the watch command running, every saved change will immediately be built locally and available in your running JupyterLab. Refresh JupyterLab to load the change in your browser (you may need to wait several seconds for the extension to be rebuilt).

By default, the jlpm run build command generates the source maps for this extension to make it easier to debug using the browser dev tools. To also generate source maps for the JupyterLab core extensions, you can run the following command:

jupyter lab build --minimize=False