# Contributing

## Bug reports, feedback

You think you have found a bug in Pylint? Well, this may be the case since Pylint is under heavy development!

Please take the time to check if it is already in the issue tracker at https://github.com/PyCQA/pylint

If you cannot find it in the tracker, create a new issue there or discuss your problem on the code-quality@python.org mailing list or using the discord server https://discord.gg/Egy6P8AMB5.

The code-quality mailing list is also a nice place to provide feedback about Pylint, since it is shared with other tools that aim at improving the quality of python code.

Note that if you don't find something you have expected in Pylint's issue tracker, it may be because it is an issue with one of its dependencies, namely astroid:

- https://github.com/PyCQA/astroid

## Discord server

https://discord.gg/Egy6P8AMB5

## Mailing lists

You can subscribe to this mailing list at https://mail.python.org/mailman/listinfo/code-quality

Archives are available at https://mail.python.org/pipermail/code-quality/

Archives before April 2013 are available at https://lists.logilab.org/pipermail/python-projects/

## Repository

Pylint is developed using the git distributed version control system.

You can clone Pylint and its dependencies from

    git clone https://github.com/PyCQA/pylint
    git clone https://github.com/PyCQA/astroid

Got a change for Pylint? Below are a few steps you should take to make sure your patch gets accepted. We recommend using Python 3.8 or higher for development of Pylint as it gives you access to the latest `ast` parser.

- Test your code

  For more information on how to use our test suite and write new tests see Testing.

- `pylint` uses black and isort among other Python autoformatters. We have a pre-commit hook which should take care of the autoformatting for you. To enable it, do the following:

  > - install `pre-commit` using `pip install pre-commit`

  > - then run `pre-commit install` in the `pylint` root directory to enable the git hooks.

- Add a short entry to the ChangeLog describing the change, except for internal implementation only changes. Not usually required, but for changes other than small bugs we also add a couple of sentences in the release document for that release, (What's New section). For the release document we usually write some more details, and it is also a good place to offer examples on how the new change is supposed to work.

- Add a short entry in `doc/whatsnew/VERSION.rst`.

- Add yourself to the CONTRIBUTORS file, flag yourself appropriately (if in doubt, you're a `contributor`).

- Write a comprehensive commit message

- Relate your change to an issue in the tracker if such an issue exists (see Closing issues via commit messages of the GitHub documentation for more information on this)

- Document your change, if it is a non-trivial one.

- Send a pull request from GitHub (see About pull requests for more insight about this topic)

## Tips for Getting Started with Pylint Development

- Read the Technical Reference. It gives a short walk through of the pylint codebase and will help you identify where you will need to make changes for what you are trying to implement.

- `astroid.extract_node()` is your friend. Most checkers are AST based, so you will likely need to interact with `astroid`. A short example of how to use `astroid.extract_node()` is given here.

- When fixing a bug for a specific check, search the code for the warning message to find where the warning is raised, and therefore where the logic for that code exists.

- When adding a new checker class you can use the `get_unused_message_id_category.py` script in `./scripts` to get a message id that is not used by any of the other checkers.

## Building the documentation

We use tox for building the documentation:

    $ tox -e docs