Metadata-Version: 2.1 Name: attrs Version: 18.2.0 Summary: Classes Without Boilerplate Home-page: https://www.attrs.org/ Author: Hynek Schlawack Author-email: hs@ox.cx Maintainer: Hynek Schlawack Maintainer-email: hs@ox.cx License: MIT Project-URL: Documentation, https://www.attrs.org/ Project-URL: Bug Tracker, https://github.com/python-attrs/attrs/issues Project-URL: Source Code, https://github.com/python-attrs/attrs Keywords: class,attribute,boilerplate Platform: UNKNOWN Classifier: Development Status :: 5 - Production/Stable Classifier: Intended Audience :: Developers Classifier: Natural Language :: English Classifier: License :: OSI Approved :: MIT License Classifier: Operating System :: OS Independent Classifier: Programming Language :: Python Classifier: Programming Language :: Python :: 2 Classifier: Programming Language :: Python :: 2.7 Classifier: Programming Language :: Python :: 3 Classifier: Programming Language :: Python :: 3.4 Classifier: Programming Language :: Python :: 3.5 Classifier: Programming Language :: Python :: 3.6 Classifier: Programming Language :: Python :: 3.7 Classifier: Programming Language :: Python :: Implementation :: CPython Classifier: Programming Language :: Python :: Implementation :: PyPy Classifier: Topic :: Software Development :: Libraries :: Python Modules Provides-Extra: docs Provides-Extra: dev Provides-Extra: tests Provides-Extra: dev Requires-Dist: coverage; extra == 'dev' Requires-Dist: hypothesis; extra == 'dev' Requires-Dist: pympler; extra == 'dev' Requires-Dist: pytest; extra == 'dev' Requires-Dist: six; extra == 'dev' Requires-Dist: zope.interface; extra == 'dev' Requires-Dist: sphinx; extra == 'dev' Requires-Dist: zope.interface; extra == 'dev' Requires-Dist: pre-commit; extra == 'dev' Provides-Extra: docs Requires-Dist: sphinx; extra == 'docs' Requires-Dist: zope.interface; extra == 'docs' Provides-Extra: tests Requires-Dist: coverage; extra == 'tests' Requires-Dist: hypothesis; extra == 'tests' Requires-Dist: pympler; extra == 'tests' Requires-Dist: pytest; extra == 'tests' Requires-Dist: six; extra == 'tests' Requires-Dist: zope.interface; extra == 'tests' .. image:: https://www.attrs.org/en/latest/_static/attrs_logo.png :alt: attrs Logo ====================================== ``attrs``: Classes Without Boilerplate ====================================== .. image:: https://readthedocs.org/projects/attrs/badge/?version=stable :target: https://www.attrs.org/en/stable/?badge=stable :alt: Documentation Status .. image:: https://travis-ci.org/python-attrs/attrs.svg?branch=master :target: https://travis-ci.org/python-attrs/attrs :alt: CI Status .. image:: https://codecov.io/github/python-attrs/attrs/branch/master/graph/badge.svg :target: https://codecov.io/github/python-attrs/attrs :alt: Test Coverage .. image:: https://img.shields.io/badge/code%20style-black-000000.svg :target: https://github.com/ambv/black :alt: Code style: black .. 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). Its main goal is to help you to write **concise** and **correct** software without slowing down your code. .. -spiel-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 >>> import attr >>> @attr.s ... class SomeClass(object): ... a_number = attr.ib(default=42) ... list_of_numbers = attr.ib(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 >>> attr.asdict(sc) {'a_number': 1, 'list_of_numbers': [1, 2, 3]} >>> SomeClass() SomeClass(a_number=42, list_of_numbers=[]) >>> C = attr.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__``, - a complete set of comparison methods, - an initializer, - and much more, *without* writing dull boilerplate code again and again and *without* runtime performance penalties. On Python 3.6 and later, you can often even drop the calls to ``attr.ib()`` by using `type annotations `_. This gives you the power to use actual classes with actual types in your code instead of confusing ``tuple``\ s or `confusingly behaving `_ ``namedtuple``\ s. Which in turn encourages you to write *small classes* that do `one thing well `_. Never again violate the `single responsibility principle `_ just because implementing ``__init__`` et al is a painful drag. .. -testimonials- Testimonials ============ **Amber Hawkie Brown**, Twisted Release Manager and Computer Owl: Writing a fully-functional class using attrs takes me less time than writing this testimonial. **Glyph Lefkowitz**, creator of `Twisted `_, `Automat `_, and other open source software, in `The One Python Library Everyone Needs `_: I’m looking forward to is being able to program in Python-with-attrs everywhere. It exerts a subtle, but positive, design influence in all the codebases I’ve see it used in. **Kenneth Reitz**, author of `Requests `_ and Developer Advocate at DigitalOcean, (`on paper no less `_!): attrs—classes for humans. I like it. **Łukasz Langa**, prolific CPython core developer and Production Engineer at Facebook: I'm increasingly digging your attr.ocity. Good job! .. -end- .. -project-information- Getting Help ============ Please use the ``python-attrs`` tag on `StackOverflow `_ to get help. Answering questions of your fellow developers is also great way to help the project! Project Information =================== ``attrs`` is released under the `MIT `_ license, its documentation lives at `Read the Docs `_, the code on `GitHub `_, and the latest release on `PyPI `_. It’s rigorously tested on Python 2.7, 3.4+, and PyPy. We collect information on **third-party extensions** in our `wiki `_. 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 `_ to get you started! Release Information =================== 18.2.0 (2018-09-01) ------------------- Deprecations ^^^^^^^^^^^^ - Comparing subclasses using ``<``, ``>``, ``<=``, and ``>=`` is now deprecated. The docs always claimed that instances are only compared if the types are identical, so this is a first step to conform to the docs. Equality operators (``==`` and ``!=``) were always strict in this regard. `#394 `_ Changes ^^^^^^^ - ``attrs`` now ships its own `PEP 484 `_ type hints. Together with `mypy `_'s ``attrs`` plugin, you've got all you need for writing statically typed code in both Python 2 and 3! At that occasion, we've also added `narrative docs `_ about type annotations in ``attrs``. `#238 `_ - Added *kw_only* arguments to ``attr.ib`` and ``attr.s``, and a corresponding *kw_only* attribute to ``attr.Attribute``. This change makes it possible to have a generated ``__init__`` with keyword-only arguments on Python 3, relaxing the required ordering of default and non-default valued attributes. `#281 `_, `#411 `_ - The test suite now runs with ``hypothesis.HealthCheck.too_slow`` disabled to prevent CI breakage on slower computers. `#364 `_, `#396 `_ - ``attr.validators.in_()`` now raises a ``ValueError`` with a useful message even if the options are a string and the value is not a string. `#383 `_ - ``attr.asdict()`` now properly handles deeply nested lists and dictionaries. `#395 `_ - Added ``attr.converters.default_if_none()`` that allows to replace ``None`` values in attributes. For example ``attr.ib(converter=default_if_none(""))`` replaces ``None`` by empty strings. `#400 `_, `#414 `_ - Fixed a reference leak where the original class would remain live after being replaced when ``slots=True`` is set. `#407 `_ - Slotted classes can now be made weakly referenceable by passing ``@attr.s(weakref_slot=True)``. `#420 `_ - Added *cache_hash* option to ``@attr.s`` which causes the hash code to be computed once and stored on the object. `#425 `_ - Attributes can be named ``property`` and ``itemgetter`` now. `#430 `_ - It is now possible to override a base class' class variable using only class annotations. `#431 `_ `Full changelog `_. Credits ======= ``attrs`` is written and maintained by `Hynek Schlawack `_. The development is kindly supported by `Variomedia AG `_. A full list of contributors can be found in `GitHub's overview `_. It’s the spiritual successor of `characteristic `_ and aspires to fix some of it clunkiness and unfortunate decisions. Both were inspired by Twisted’s `FancyEqMixin `_ but both are implemented using class decorators because `subclassing is bad for you `_, m’kay?