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.

Implement Features

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

Write Documentation

Helios could always use more documentation, whether as part of the official Helios docs, in docstrings, or even on the web in blog posts, articles, and such. Helios uses [Sphinx]( to generate documentation. Please follow the [numpy coding style]( - and of course - [PEP8]( for docstring documentation.

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!

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. Put your new functionality into a function with a docstring, and add the feature to the list in

  3. The pull request should work for Python3.7, 3.8, 3.9 and for PyPy.

Publishing Releases

Checklist before Releasing

  • Review the open list of Helios issues. Check whether there are outstanding issues that can be closed, and whether there are any issues that should delay the release. Label them !

  • Review and update the release notes. Review and update the Changelog file. Get a partial list of contributors with something like:

    git shortlog -nse v0.1.0..

    where v0.1.0 was the last release tag name.

    Then manually go over git shortlog v0.1.0.. to make sure the release notes are as complete as possible and that every contributor was recognized.

  • Use the opportunity to update the .mailmap file if there are any duplicate authors listed from git shortlog -ns.

  • Add any new authors to the AUTHORS file.

  • Check the copyright years in docs/source/ and LICENSE

  • Check the examples and tutorial - we really need an automated check here.

  • Make sure all tests pass on your local machine (from the <helios root> directory):

    cd ..
    pytest -s --verbose --doctest-modules helios
    cd helios # back to the root directory
  • Check the documentation doctests:

    cd docs
    make -C . html
    cd ..
  • The release should now be ready.

Doing the release

  • Update release-history.rst in the documentation if you have not done so already. You may also highlight any additions, improvements, and bug fixes.

  • Type git status and check that you are on the master branch with no uncommitted code.

  • Now it’s time for the source release. Mark the release with an empty commit, just to leave a marker. It makes it easier to find the release when skimming through the git history:

    git commit --allow-empty -m "REL: vX.Y.Z"
  • Tag the commit:

    git tag -am 'Second public release' vX.Y.Z  # Don't forget the leading v

    This will create a tag named vX.Y.Z. The -a flag (strongly recommended) opens up a text editor where you should enter a brief description of the release.

  • Verify that the __version__ attribute is correctly updated:

    import helios
    helios.__version__  # should be 'X.Y.Z'

    Incidentally, once you resume development and add the first commit after this tag, __version__ will take on a value like X.Y.Z+1.g58ad5f7, where +1 means “1 commit past version X.Y.Z” and 58ad5f7 is the first 7 characters of the hash of the current commit. The letter g stands for “git”. This is all managed automatically by versioneer and in accordance with the specification in PEP 440.

  • Push the new commit and the tag to master:

    git push origin master
    git push origin vX.Y.Z
  • Register for a PyPI account and Install twine, a tool for uploading packages to PyPI:

    python3 -m pip install --upgrade twine
  • Remove any extraneous files:

    git clean -dfx

    If you happen to have any important files in your project directory that are not committed to git, move them first; this will delete them!

  • Publish a release on PyPI:

    python sdist
    python bdist_wheel
    twine upload dist/*
  • Check how everything looks on pypi - the description, the packages. If necessary delete the release and try again if it doesn’t look right.

  • Set up maintenance / development branches

    If this is this is a full release you need to set up two branches, one for further substantial development (often called ‘trunk’) and another for maintenance releases.

    • Branch to maintenance:

      git co -b maint/X.Y.Z

      Push with something like git push upstream-rw maint/0.6.x --set-upstream

    • Start next development series:

      git co main-master

      Next merge the maintenace branch with the “ours” strategy. This just labels the maintenance branch edits as seen but discarded, so we can merge from maintenance in future without getting spurious merge conflicts:

      git merge -s ours maint/0.6.x

      Push with something like git push upstream-rw main-master:master

    If this is just a maintenance release from maint/0.6.x or similar, just tag and set the version number to - say -

  • Push the tag with git push upstream-rw 0.6.0