Contributing to PRAW

PRAW gladly welcomes new contributions. As with most larger projects, we have an established consistent way of doing things. A consistent style increases readability, decreases bug-potential and makes it faster to understand how everything works together.

PRAW follows PEP 8 and PEP 257. pre-commit is used to manage a suite of pre-commit hooks that enforce conformance with these PEPs along with several other checks. Additionally, the pre_push.py script can be used to run the full pre-commit suite and the docs build prior to submitting a pull request. The following are PRAW-specific guidelines in addition to those PEPs.

Note

In order to use the pre-commit hooks and the pre_push.py dependencies, install PRAW’s [lint] extra, followed by the appropriate pre-commit command:

pip install praw[lint]
pre-commit install

If you are using zsh for your shell, you will need to double-quote "praw[lint]" like so:

pip install "praw[lint]"
pre-commit install

Code

Within a single file classes are sorted alphabetically where inheritance permits.
Within a class, methods are sorted alphabetically within their respective groups with the following as the grouping order:
- Static methods
- Class methods
- Cached properties
- Properties
- Instance Methods
Use descriptive names for the catch-all keyword argument. E.g., **other_options rather than **kwargs.

Methods with more than one argument should have all its arguments sorted alphabetically and marked as keyword only with the * argument. For example:

class ExampleClass:
    def example_method(
        self,
        *,
        arg1,
        arg2,
        optional_arg1=None,
    ):
        ...

There is some exceptions to this:

If it’s clear without reading documentation what the mandatory positional arguments would be and their order, then they can be positional arguments. For example:
```
class ExampleClass:
    def pair(self, left, right):
        ...
```

If there is one or two mandatory arguments and some optional arguments, then the mandatory arguments may be positional (as long as it adheres to the previous point), however, the optional arguments must be made keyword only and sorted alphabetically. For example:

class Subreddit:
    def submit(
        self,
        title,
        *,
        collection_id=None,
        discussion_type=None,
        draft_id=None,
        flair_id=None,
        flair_text=None,
        inline_media=None,
        nsfw=False,
        resubmit=True,
        selftext=None,
        send_replies=True,
        spoiler=False,
        url=None,
    ):
        ...

Testing

Contributions to PRAW requires 100% test coverage as reported by Coveralls. If you know how to add a feature, but aren’t sure how to write the necessary tests, please open a pull request anyway so we can work with you to write the necessary tests.

Running the Test Suite

GitHub Actions automatically runs all updates to known branches and pull requests. However, it’s useful to be able to run the tests locally. The simplest way is via:

pytest

Without any configuration or modification, all the tests should pass. If they do not, please file a bug report.

Adding and Updating Integration Tests

PRAW’s integration tests utilize Betamax to record an interaction with Reddit. The recorded interaction is then replayed for subsequent test runs.

To safely record a cassette without leaking your account credentials, PRAW utilizes a number of environment variables which are replaced with placeholders in the cassettes. The environment variables are (listed in bash export format):

export prawtest_client_id=myclientid
export prawtest_client_secret=myclientsecret
export prawtest_password=mypassword
export prawtest_test_subreddit=test
export prawtest_username=myusername
export prawtest_user_agent=praw_pytest

By setting these environment variables prior to running pytest, when adding or updating cassettes, instances of mypassword will be replaced by the placeholder text <PASSWORD> and similar for the other environment variables.

To use a refresh token instead of username/password set prawtest_refresh_token instead of prawtest_password and prawtest_username.

When adding or updating a cassette, you will likely want to force requests to occur again rather than using an existing cassette. The simplest way to rebuild a cassette is to first delete it, and then rerun the test suite.

Please always verify that only the requests you expect to be made are contained within your cassette.

Documentation

All publicly available functions, classes, and modules should have a docstring.
All documentation files and docstrings should be linted and formatted by docstrfmt.
Use correct terminology. A subreddit’s fullname is something like t5_xyfc7. The correct term for a subreddit’s “name” like python is its display name.

Static Checker

PRAW’s test suite comes with a checker tool that can warn you of using incorrect documentation styles (using .. code:: instead of .. code-block::, using /r/ instead of r/, etc.). This is run automatically by the pre-commit hooks and the pre_push.py script.

Files to Update

AUTHORS.rst

For your first contribution, please add yourself to the end of the respective list in the AUTHORS.rst file.

CHANGES.rst

For feature additions, bugfixes, or code removal please add an appropriate entry to CHANGES.rst. If the Unreleased section does not exist at the top of CHANGES.rst please add it. See commit 280525c16ba28cdd69cdbb272a0e2764b1c7e6a0 for an example.