| .. raw:: html |
| |
| <p align="center"> |
| <a href="https://www.attrs.org/"> |
| <img src="./docs/_static/attrs_logo.svg" width="35%" alt="attrs" /> |
| </a> |
| </p> |
| <p align="center"> |
| <a href="https://www.attrs.org/en/stable/?badge=stable"> |
| <img src="https://img.shields.io/badge/Docs-Read%20The%20Docs-black" alt="Documentation" /> |
| </a> |
| <a href="https://github.com/python-attrs/attrs/blob/main/LICENSE"> |
| <img src="https://img.shields.io/badge/license-MIT-C06524" alt="License: MIT" /> |
| </a> |
| <a href="https://pypi.org/project/attrs/"> |
| <img src="https://img.shields.io/pypi/v/attrs" /> |
| </a> |
| </p> |
| |
| .. teaser-begin |
| |
| ``attrs`` is the Python package that will bring back the **joy** of **writing classes** by relieving you from the drudgery of implementing object protocols (aka `dunder methods <https://www.attrs.org/en/latest/glossary.html#term-dunder-methods>`_). |
| `Trusted by NASA <https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-github-profile/customizing-your-profile/personalizing-your-profile#list-of-qualifying-repositories-for-mars-2020-helicopter-contributor-badge>`_ for Mars missions since 2020! |
| |
| Its main goal is to help you to write **concise** and **correct** software without slowing down your code. |
| |
| .. teaser-end |
| |
| For that, it gives you a class decorator and a way to declaratively define the attributes on that class: |
| |
| .. -code-begin- |
| |
| .. code-block:: pycon |
| |
| >>> from attrs import asdict, define, make_class, Factory |
| |
| >>> @define |
| ... class SomeClass: |
| ... a_number: int = 42 |
| ... list_of_numbers: list[int] = Factory(list) |
| ... |
| ... def hard_math(self, another_number): |
| ... return self.a_number + sum(self.list_of_numbers) * another_number |
| |
| |
| >>> sc = SomeClass(1, [1, 2, 3]) |
| >>> sc |
| SomeClass(a_number=1, list_of_numbers=[1, 2, 3]) |
| |
| >>> sc.hard_math(3) |
| 19 |
| >>> sc == SomeClass(1, [1, 2, 3]) |
| True |
| >>> sc != SomeClass(2, [3, 2, 1]) |
| True |
| |
| >>> asdict(sc) |
| {'a_number': 1, 'list_of_numbers': [1, 2, 3]} |
| |
| >>> SomeClass() |
| SomeClass(a_number=42, list_of_numbers=[]) |
| |
| >>> C = make_class("C", ["a", "b"]) |
| >>> C("foo", "bar") |
| C(a='foo', b='bar') |
| |
| |
| After *declaring* your attributes ``attrs`` gives you: |
| |
| - a concise and explicit overview of the class's attributes, |
| - a nice human-readable ``__repr__``, |
| - equality-checking methods, |
| - an initializer, |
| - and much more, |
| |
| *without* writing dull boilerplate code again and again and *without* runtime performance penalties. |
| |
| **Hate type annotations**!? |
| No problem! |
| Types are entirely **optional** with ``attrs``. |
| Simply assign ``attrs.field()`` to the attributes instead of annotating them with types. |
| |
| ---- |
| |
| This example uses ``attrs``'s modern APIs that have been introduced in version 20.1.0, and the ``attrs`` package import name that has been added in version 21.3.0. |
| The classic APIs (``@attr.s``, ``attr.ib``, plus their serious business aliases) and the ``attr`` package import name will remain **indefinitely**. |
| |
| Please check out `On The Core API Names <https://www.attrs.org/en/latest/names.html>`_ for a more in-depth explanation. |
| |
| |
| Data Classes |
| ============ |
| |
| On the tin, ``attrs`` might remind you of ``dataclasses`` (and indeed, ``dataclasses`` `are a descendant <https://hynek.me/articles/import-attrs/>`_ of ``attrs``). |
| In practice it does a lot more and is more flexible. |
| For instance it allows you to define `special handling of NumPy arrays for equality checks <https://www.attrs.org/en/stable/comparison.html#customization>`_, or allows more ways to `plug into the initialization process <https://www.attrs.org/en/stable/init.html#hooking-yourself-into-initialization>`_. |
| |
| For more details, please refer to our `comparison page <https://www.attrs.org/en/stable/why.html#data-classes>`_. |
| |
| |
| .. -getting-help- |
| |
| Getting Help |
| ============ |
| |
| Please use the ``python-attrs`` tag on `Stack Overflow <https://stackoverflow.com/questions/tagged/python-attrs>`_ to get help. |
| |
| Answering questions of your fellow developers is also a great way to help the project! |
| |
| |
| .. -project-information- |
| |
| Project Information |
| =================== |
| |
| ``attrs`` is released under the `MIT <https://choosealicense.com/licenses/mit/>`_ license, |
| its documentation lives at `Read the Docs <https://www.attrs.org/>`_, |
| the code on `GitHub <https://github.com/python-attrs/attrs>`_, |
| and the latest release on `PyPI <https://pypi.org/project/attrs/>`_. |
| It’s rigorously tested on Python 2.7, 3.5+, and PyPy. |
| |
| We collect information on **third-party extensions** in our `wiki <https://github.com/python-attrs/attrs/wiki/Extensions-to-attrs>`_. |
| Feel free to browse and add your own! |
| |
| If you'd like to contribute to ``attrs`` you're most welcome and we've written `a little guide <https://github.com/python-attrs/attrs/blob/main/.github/CONTRIBUTING.md>`_ to get you started! |
| |
| |
| ``attrs`` for Enterprise |
| ------------------------ |
| |
| Available as part of the Tidelift Subscription. |
| |
| The maintainers of ``attrs`` and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source packages you use to build your applications. |
| Save time, reduce risk, and improve code health, while paying the maintainers of the exact packages you use. |
| `Learn more. <https://tidelift.com/subscription/pkg/pypi-attrs?utm_source=pypi-attrs&utm_medium=referral&utm_campaign=enterprise&utm_term=repo>`_ |