First off, thank you for considering contributing to attrs
!
It's people like you who make it is such a great tool for everyone.
This document is mainly to help you to get started by codifying tribal knowledge and expectations and make it more accessible to everyone. But don't be afraid to open half-finished PRs and ask questions if something is unclear!
In case you'd like to help out but don't want to deal with GitHub, there's a great opportunity: help your fellow developers on StackOverflow!
The offical tag is python-attrs
and helping out in support frees us up for improving attrs
instead!
- No contribution is too small! Please submit as many fixes for typos and grammar bloopers as you can!
- Try to limit each pull request to one change only.
- Always add tests and docs for your code. This is a hard rule; patches with missing tests or documentation can't be merged.
- Make sure your changes pass our CI. You won't get any feedback until it's green unless you ask for it.
- Once you've addressed review feedback, make sure to bump the pull request with a short note, so we know you're done.
- Don’t break backward compatibility.
Obey PEP 8 and PEP 257. We use the
"""
-on-separate-lines style for docstrings:def func(x): """ Do something. :param str x: A very important parameter. :rtype: str """
If you add or change public APIs, tag the docstring using
.. versionadded:: 16.0.0 WHAT
or.. versionchanged:: 16.2.0 WHAT
.Prefer double quotes (
"
) over single quotes ('
) unless the string contains double quotes itself.
Write your asserts as
expected == actual
to line them up nicely:x = f() assert 42 == x.some_attribute assert "foo" == x._a_private_attribute
To run the test suite, all you need is a recent tox. It will ensure the test suite runs with all dependencies against all Python versions just as it will on Travis CI. If you lack some Python versions, you can can always limit the environments like
tox -e py27,py35
(in that case you may want to look into pyenv, which makes it very easy to install many different Python versions in parallel).Write good test docstrings.
To ensure new features work well with the rest of the system, they should be also added to our Hypothesis testing strategy which you find in
tests/util.py
.
Use semantic newlines in reStructuredText files (files ending in
.rst
):This is a sentence. This is another sentence.
If you start a new section, add two blank lines before and one blank line after the header except if two headers follow immediately after each other:
Last line of previous section. Header of New Top Section ------------------------- Header of New Section ^^^^^^^^^^^^^^^^^^^^^ First line of new section.
If you add a new feature, demonstrate its awesomeness in the examples page!
If your change is noteworthy, there needs to be a changelog entry, so our users can learn about it!
To avoid merge conflicts, we use the towncrier package to manage our changelog.
towncrier
uses independent files for each pull request -- so called news fragments -- instead of one monolithic changelog file.
On release those news fragments are compiled into our CHANGELOG.rst
.
You don't need to install towncrier
yourself, you just have to abide to a few simple rules:
- For each pull request, add a new file into
changelog.d
with a filename adhering to thepr#.(change|deprecation|breaking).rst
schema: For examplechangelog.d/42.change.rst
for a non-breaking change, that is proposed in pull request number 42. - As with other docs, please use semantic newlines within news fragments.
- Wrap symbols like modules, functions, or classes into double backticks so they are rendered in a monospaced font.
- If you mention functions or other callables, add parantheses at the end of their names:
attr.func()
orattr.Class.method()
. This makes the changelog a lot more readable. - Prefer simple past or constructions with "now".
For example:
- Added
attr.validators.func()
. attr.func()
now doesn't crash the Large Hadron Collider anymore.
- Added
- If you want to reference multiple issues, copy the news fragment to another filename.
towncrier
will merge all news fragments with identical contents into one entry with multiple links to the respective pull requests.
Example entries:
Added ``attr.validators.func()``. The feature really *is* awesome.
or:
``attr.func()`` now doesn't crash the Large Hadron Collider anymore. The bug really *was* nasty.
tox -e changelog
will render the current changelog to the terminal if you have any doubts.
You can (and should) run our test suite using tox.
However you’ll probably want a more traditional environment too.
We highly recommend to develop using the latest Python 3 release because attrs
tries to take advantage of modern features whenever possible.
First create a virtual environment. It’s out of scope for this document to list all the ways to manage virtual environments in Python but if you don’t have already a pet way, take some time to look at tools like pew, virtualfish, and virtualenvwrapper.
Next get an up to date checkout of the attrs
repository:
git checkout [email protected]:python-attrs/attrs.git
Change into the newly created directory and after activating your virtual environment install an editable version of attrs
:
cd attrs
pip install -e .
If you run the virtual environment’s Python and try to import attr
it should work!
To run the test suite, you'll need our development dependencies which can be installed using
pip install -r dev-requirements.txt
At this point
python -m pytest
should work and pass!
attrs
is maintained by team of volunteers that is always open for new members that share our vision of a fast, lean, and magic-free library that empowers programmers to write better code with less effort.
If you'd like to join, just get a pull request merged and ask to be added in the very same pull request!
The simple rule is that everyone is welcome to review/merge pull requests of others but nobody is allowed to merge their own code.
Hynek Schlawack acts reluctantly as the BDFL and has the final say over design decisions.
Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms. Please report any harm to Hynek Schlawack in any way you find appropriate.
Thank you for considering contributing to attrs
!