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attrs: Attributes without boilerplate.
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.. teaser-begin
``attrs`` is an `MIT <http://choosealicense.com/licenses/mit/>`_-licensed Python package with class decorators that ease the chores of implementing the most common attribute-related object protocols:
.. code-block:: pycon
>>> import attr
>>> @attr.s
... class C(object):
... x = attr.ib(default=42)
... y = attr.ib(default=attr.Factory(list))
>>> i = C(x=1, y=2)
>>> i
C(x=1, y=2)
>>> i == C(1, 2)
True
>>> i != C(2, 1)
True
>>> attr.asdict(i)
{'y': 2, 'x': 1}
>>> C()
C(x=42, y=[])
>>> C2 = attr.make_class("C2", ["a", "b"])
>>> C2("foo", "bar")
C2(a='foo', b='bar')
(If you don’t like the playful ``attr.s`` and ``attr.ib``, you can also use their no-nonsense aliases ``attr.attributes`` and ``attr.attr``).
You just specify the attributes to work with and ``attrs`` gives you:
- a nice human-readable ``__repr__``,
- a complete set of comparison methods,
- an initializer,
- and much more
*without* writing dull boilerplate code again and again.
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.
So put down that type-less data structures and welcome some class into your life!
.. note::
I wrote an `explanation <https://attrs.readthedocs.org/en/latest/why.html#characteristic>`_ on why I forked my own ``characteristic``.
It's not dead but ``attrs`` will have more new features.
``attrs``\ ’s documentation lives at `Read the Docs <https://attrs.readthedocs.org/>`_, the code on `GitHub <https://github.com/hynek/attrs>`_.
It’s rigorously tested on Python 2.6, 2.7, 3.3+, and PyPy.
Authors
-------
``attrs`` is written and maintained by `Hynek Schlawack <https://hynek.me/>`_.
The development is kindly supported by `Variomedia AG <https://www.variomedia.de/>`_.
It’s the spiritual successor of `characteristic <https://characteristic.readthedocs.org/>`_ and aspires to fix some of it clunkiness and unfortunate decisions. Both were inspired by Twisted’s `FancyEqMixin <https://twistedmatrix.com/documents/current/api/twisted.python.util.FancyEqMixin.html>`_ but both are implemented using class decorators because `sub-classing is bad for you <https://www.youtube.com/watch?v=3MNVP9-hglc>`_, m’kay?
The following folks helped forming ``attrs`` into what it is now:
- `Glyph <https://github.com/glyph/>`_
- `HawkOwl <https://github.com/hawkowl>`_
- `Lynn Root <https://github.com/econchick>`_
- `Wouter Bolsterlee <https://github.com/wbolster/>`_
Of course ``characteristic``\ ’s `hall of fame <https://characteristic.readthedocs.org/en/stable/license.html>`_ applies as well since they share a lot of code.
