Contributing to FairLens#

fairlens is an open source project currently under active development. As such, we appreciate any contributions from the community. There are many ways you can get involved: filing feature requests or bug reports on our issue tracker, updating the documentation, or making pull requests for new features you have developed or bugs you have fixed.

Getting started#

  1. Fork the fairlens repo on GitHub.

  2. Clone your fork locally:

$ git clone
  1. Set up the development environment. We highly recommend using a virtual environment when developing fairlens. The most basic approach is to use venv, which comes by default in Python 3. You can create and activate an environment named .env with:

python3 -m venv .env
# activate environment
source .env/bin/activate

Other tools such as virtualenv and conda are also suitable. Pick your favourite!

Once your environment is active, you can install fairlens and all dependencies by running:

pip install -e .[dev,doc,test]

Additionally, we use the pre-commit tool for linting and style checks. This will run flake8 and mypy for linting and static type checking, as well as isort and black for style formatting on every commit. An up to date list of pre-commit checks can be found in the .pre-commit-config.yaml file.

To install the pre-commit hooks in your development environment, run

pip install pre-commit
pre-commit install
  1. Create a development branch

   git checkout -b name-of-your-bugfix-or-feature-branch

Now you can start making changes in your local version of ``fairlens``.
  1. Run tests, and make sure they pass. We use the pytest tool to create and run unit tests.


All tests should go in the tests subdirectory of the fairlens repo.

  1. Commit and push your changes to GitHub

git push origin name-of-your-bugfix-or-feature
  1. Create a pull request (PR) through GitHub.

If you are improving or modifying the documentation, then you should be familiar with sphinx and writing reStructuredText .rst files. All documentation is found in the docs subdirectory of the repo.

To build the documentation run

cd docs
make html

This will create static html files in the _build folder that can be viewed in your web browser.

Pull Request Guidelines#

Before you submit a pull request, check that it meets the following guidelines:

  • The pull request must include tests that cover the functionality you have added. If fixing a bug, include a test that passes with the bug fix.

  • If adding new functionality the documentation must be updated. All documentation must be included in the docs subdirectory and be built using sphinx.

fairlens will use GitHub Actions to run CI workflows on your PR. All workflows must pass before your PR will be reviewed and accepted.