Contributions are welcome, and they are greatly appreciated! Every little bit helps, and credit will always be given.

You can contribute in many ways:

Types of Contributions

Report Bugs

Report bugs at

If you are reporting a bug, please include:

  • Any details about your local setup that might be helpful in troubleshooting.

  • Detailed steps to reproduce the bug.

Fix Bugs

Look through the GitHub issues for bugs. Anything tagged with “bug” is open to whoever wants to implement it.

Write Documentation

This could always use more documentation, whether as part of the official docs, in docstrings, or even on the web in blog posts, articles, and such.

Documentation is built automatically on every push using Read the Docs.

Submit Feedback

The best way to send feedback is to file an issue at

If you are proposing a feature:

  • Explain in detail how it would work.

  • Keep the scope as narrow as possible, to make it easier to implement.

  • Remember that this is a volunteer-driven project, and that contributions are welcome :)

Get Started!

Useful Reading

Ready to contribute? Here’s how to set up collections-extended for local development.

  1. Fork the collections-extended repo on GitHub.

  2. Clone your fork locally:

    $ git clone
  3. Make sure you are excluding your editor’s files from the repo

    We don’t want to use the project’s gitignore to exclude every editor’s files, so set up your global gitignore. See:

  4. Install your local copy into a virtualenv:

    $ cd collections-extended
    $ python -m venv .venv
    $ . .venv/bin/activate
    $ pip install -r requirements.txt
  5. Create a branch for local development:

    $ git checkout -b name-of-your-bugfix-or-feature
  6. Make your changes locally.

  7. When you’re done making changes, check that your changes pass flake8 and the tests, including testing other Python versions with tox:

    $ flake8
    $ py.test
    $ tox
  8. Commit your changes and push your branch to GitHub:

    $ git add .
    $ git commit -m "Your detailed description of your changes."
    $ git push origin name-of-your-bugfix-or-feature
  9. Submit a pull request through the GitHub website.

Pull Request Guidelines

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

  1. The pull request should include tests.

  2. If the pull request adds functionality, the docs should be updated.

  3. The pull request should work for all supported versions. Check and make sure that the tests pass for all supported Python versions.

  4. Add the feature/bug to the appropriate section in HISTORY.rst

  5. Review and update the relevant docs.


To run a subset of tests:

$ py.test tests/
$ py.test tests/