Developing Jupytext

How to test development versions from GitHub

If you want to test a feature that has been integrated in main but not delivered yet to pip or conda, use

HATCH_BUILD_HOOKS_ENABLE=true pip install git+

The above requires node. You can install it with e.g.

conda install 'nodejs>=20' -c conda-forge

Alternatively you can build only Jupytext core (e.g. skip the JupyterLab extension). To do so, remove HATCH_BUILD_HOOKS_ENABLE=true in the above.

Finally, if you want to test a development branch, use

HATCH_BUILD_HOOKS_ENABLE=true pip install git+

where branch is the name of the branch you want to test.

Install and develop Jupytext locally

Most of Jupytext’s code is written in Python. To develop the Python part of Jupytext, you should clone Jupytext, then create a dedicated Python env:

conda env create --file environment.yml  # or conda env update --file ...
conda activate jupytext-dev

Install the jupytext package in development mode with

HATCH_BUILD_HOOKS_ENABLE=true pip install -e '.[dev]'

We use the pre-commit package to run pre-commit scripts like black and ruff on the code. Install it with

pre-commit install

Tests are executed with pytest. You can run them in parallel with for instance

pytest -n 5

Some tests require a Jupyter kernel pointing to the current environment:

python -m ipykernel install --name jupytext-dev --user

Jupytext’s extension for JupyterLab

Our extension for JupyterLab adds a series of Jupytext commands to JupyterLab. The code is in packages/labextension. See the there for instructions on how to develop that extension.

Jupytext’s documentation

Install the documentation tools with

conda env create --file docs/environment.yml
conda activate jupytext-docs
cd docs

and build the HTML documentation locally with

rm -rf _build
make html