You want to add some code to WeasyPrint, launch its tests or improve its documentation? Thank you very much! Here are some tips to help you play with WeasyPrint in good conditions.

The first step is to clone the repository, create a virtual environment and install WeasyPrint dependencies.

git clone
cd WeasyPrint
python -m venv venv
venv/bin/pip install .[doc,test]

You can then let your terminal in the current directory and launch Python to test your changes. import weasyprint will then import the working directory code, so that you can modify it and test your changes.


Code & Issues

If you’ve found a bug in WeasyPrint, it’s time to report it, and to fix it if you can!

You can report bugs and feature requests on GitHub. If you want to add or fix some code, please fork the repository and create a pull request, we’ll be happy to review your work.

You can find more information about the code architecture in the Dive into the Source section.


Tests are stored in the tests folder at the top of the repository. They use the pytest library.

You can launch tests (with code coverage and lint) using the following command:

venv/bin/python -m pytest


Documentation is stored in the docs folder at the top of the repository. It relies on the Sphinx library.

You can build the documentation using the following command:

venv/bin/sphinx-build docs docs/_build

The documentation home page can now be found in the /path/to/weasyprint/docs/_build/index.html file. You can open this file in a browser to see the final rendering.