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:

  • Your operating system name and version.

  • 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” and “help wanted” is open to whoever wants to implement it.

Implement Features

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

Write Documentation

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

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!

ELFI is a project with dozens of collaborators, so organization is key to making our contributions effective and avoid reword. Thus, in addition to the recommendations below we strongly recommend reading our Wiki to see what is the suggested git workflow procedure for your type of contribution.

Ready to contribute? Here’s how to set up ELFI for local development.

  1. Fork the elfi repo on GitHub.

  2. Clone your fork locally and add the base repository as a remote:

    $ git clone
    $ cd elfi
    $ git remote add upstream
  3. Make sure you have Python 3 and Anaconda Distribution installed on your machine. Check your conda and Python versions. Currently supported Python versions are 3.9, 3.10, 3.11, 3.12:

    $ conda -V
    $ python -V
  4. Install your local copy and the development requirements into a conda environment. You may need to replace “3.9” in the first line with the python version printed in the previous step:

    $ conda create -n elfi python=3.9 numpy
    $ source activate elfi
    $ cd elfi
    $ make dev
  5. Create a branch for local development:

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

    Now you can make your changes locally.

  6. Follow the Style Guidelines

  7. When you’re done making changes, check that your changes pass flake8 and the tests:

    $ make lint
    $ make test

    You may run make test-notslow instead of make test as long as your proposed changes are unrelated to BOLFI.

    Also make sure that the docstrings of your code are formatted properly:

    $ make docs
  8. Commit your changes and push your branch to GitHub:

    $ git add .
    $ git commit -m "Your detailed description of your changes."
  9. After committing your changes, you may sync with the base repository if there has been changes::

    $ git fetch upstream $ git rebase upstream/dev

  10. Push the changes:: $ git push origin name-of-your-bugfix-or-feature

  11. Submit a pull request through the GitHub website.

Style Guidelines

The Python code in ELFI mostly follows PEP8, which is considered the de-facto code style guide for Python. Lines should not exceed 100 characters.

Docstrings follow the NumPy style.

Pull Request Guidelines

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

  1. The pull request should include tests that will be run automatically using Github Actions.

  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 Python 3.9 and later. Check and make sure that the tests pass for all supported Python versions.


To run a subset of tests:

$ py.test tests.test_elfi