Update attrs to 17.4.0

[pyup-bot]

There's a new version of attrs available.
You are currently using 16.2.0. I have updated it to 17.4.0

These links might come in handy: PyPI | Changelog | Homepage

Changelog

17.4.0

---

Backward-incompatible Changes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

• The traversal of MROs when using multiple inheritance was backward:
  If you defined a class C that subclasses A and B like C(A, B), attrs would have collected the attributes from B before those of A.

This is now fixed and means that in classes that employ multiple inheritance, the output of __repr__ and the order of positional arguments in __init__ changes.
Due to the nature of this bug, a proper deprecation cycle was unfortunately impossible.

Generally speaking, it's advisable to prefer kwargs-based initialization anyways – especially if you employ multiple inheritance and diamond-shaped hierarchies.

298 <https://github.com/python-attrs/attrs/issues/298>,
299 <https://github.com/python-attrs/attrs/issues/299>,
304 <https://github.com/python-attrs/attrs/issues/304>_

• The __repr__ set by attrs
  no longer produces an AttributeError
  when the instance is missing some of the specified attributes
  (either through deleting
  or after using init=False on some attributes).

This can break code
that relied on repr(attr_cls_instance) raising AttributeError
to check if any attr-specified members were unset.

If you were using this,
you can implement a custom method for checking this::

 def has_unset_members(self):
     for field in attr.fields(type(self)):
         try:
             getattr(self, field.name)
         except AttributeError:
             return True
     return False

308 <https://github.com/python-attrs/attrs/issues/308>_

Deprecations
^^^^^^^^^^^^

• The attr.ib(convert=callable) option is now deprecated in favor of attr.ib(converter=callable).

This is done to achieve consistency with other noun-based arguments like validator.

convert will keep working until at least January 2019 while raising a DeprecationWarning.

307 <https://github.com/python-attrs/attrs/issues/307>_

Changes
^^^^^^^

• Generated __hash__ methods now hash the class type along with the attribute values.
  Until now the hashes of two classes with the same values were identical which was a bug.

The generated method is also much faster now.

261 <https://github.com/python-attrs/attrs/issues/261>,
295 <https://github.com/python-attrs/attrs/issues/295>,
296 <https://github.com/python-attrs/attrs/issues/296>_

• attr.ib\ ’s metadata argument now defaults to a unique empty dict instance instead of sharing a common empty dict for all.
  The singleton empty dict is still enforced.

280 <https://github.com/python-attrs/attrs/issues/280>_

• ctypes is optional now however if it's missing, a bare super() will not work in slots classes.
  This should only happen in special environments like Google App Engine.

284 <https://github.com/python-attrs/attrs/issues/284>,
286 <https://github.com/python-attrs/attrs/issues/286>

• The attribute redefinition feature introduced in 17.3.0 now takes into account if an attribute is redefined via multiple inheritance.
  In that case, the definition that is closer to the base of the class hierarchy wins.

285 <https://github.com/python-attrs/attrs/issues/285>,
287 <https://github.com/python-attrs/attrs/issues/287>

• Subclasses of auto_attribs=True can be empty now.

291 <https://github.com/python-attrs/attrs/issues/291>,
292 <https://github.com/python-attrs/attrs/issues/292>

• Equality tests are much faster now.

306 <https://github.com/python-attrs/attrs/issues/306>_

• All generated methods now have correct __module__, __name__, and (on Python 3) __qualname__ attributes.

309 <https://github.com/python-attrs/attrs/issues/309>_

---

17.3.0

---

Backward-incompatible Changes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

• Attributes are not defined on the class body anymore.

This means that if you define a class C with an attribute x, the class will not have an attribute x for introspection anymore.
Instead of C.x, use attr.fields(C).x or look at C.__attrs_attrs__.
The old behavior has been deprecated since version 16.1.
(253 <https://github.com/python-attrs/attrs/issues/253>_)

Changes
^^^^^^^

• super() and __class__ now work on Python 3 when slots=True.
  (102 <https://github.com/python-attrs/attrs/issues/102>, 226 <https://github.com/python-attrs/attrs/issues/226>, 269 <https://github.com/python-attrs/attrs/issues/269>, 270 <https://github.com/python-attrs/attrs/issues/270>, 272 <https://github.com/python-attrs/attrs/issues/272>_)
• Added type argument to attr.ib() and corresponding type attribute to attr.Attribute.

This change paves the way for automatic type checking and serialization (though as of this release attrs does not make use of it).
In Python 3.6 or higher, the value of attr.Attribute.type can alternately be set using variable type annotations
(see PEP 526 <https://www.python.org/dev/peps/pep-0526/>). (151 <https://github.com/python-attrs/attrs/issues/151>, 214 <https://github.com/python-attrs/attrs/issues/214>, 215 <https://github.com/python-attrs/attrs/issues/215>, 239 <https://github.com/python-attrs/attrs/issues/239>_)

• The combination of str=True and slots=True now works on Python 2.
  (198 <https://github.com/python-attrs/attrs/issues/198>_)
• attr.Factory is hashable again. (204 <https://github.com/python-attrs/attrs/issues/204>_)
• Subclasses now can overwrite attribute definitions of their superclass.

That means that you can -- for example -- change the default value for an attribute by redefining it.
(221 <https://github.com/python-attrs/attrs/issues/221>, 229 <https://github.com/python-attrs/attrs/issues/229>)

• Added new option auto_attribs to attr.s that allows to collect annotated fields without setting them to attr.ib().

Setting a field to an attr.ib() is still possible to supply options like validators.
Setting it to any other value is treated like it was passed as attr.ib(default=value) -- passing an instance of attr.Factory also works as expected.
(262 <https://github.com/python-attrs/attrs/issues/262>, 277 <https://github.com/python-attrs/attrs/issues/277>)

• Instances of classes created using attr.make_class() can now be pickled.
  (282 <https://github.com/python-attrs/attrs/issues/282>_)

---

17.2.0

---

Changes:
^^^^^^^^

• Validators are hashable again.
  Note that validators may become frozen in the future, pending availability of no-overhead frozen classes.
  192 <https://github.com/python-attrs/attrs/issues/192>_

---

17.1.0

---

To encourage more participation, the project has also been moved into a dedicated GitHub organization <https://github.com/python-attrs/>_ and everyone is most welcome to join!

attrs also has a logo now!

.. image:: http://www.attrs.org/en/latest/_static/attrs_logo.png
:alt: attrs logo

Backward-incompatible Changes:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

• attrs will set the __hash__() method to None by default now.
  The way hashes were handled before was in conflict with Python's specification <https://docs.python.org/3/reference/datamodel.htmlobject.__hash__>.
  This may break some software although this breakage is most likely just surfacing of latent bugs.
  You can always make attrs create the __hash__() method using attr.s(hash=True).
  See 136 for the rationale of this change.

.. warning::

Please do not upgrade blindly and do test your software!
Especially if you use instances as dict keys or put them into sets!

• Correspondingly, attr.ib's hash argument is None by default too and mirrors the cmp argument as it should.

Deprecations:
^^^^^^^^^^^^^

• attr.assoc() is now deprecated in favor of attr.evolve() and will stop working in 2018.

Changes:
^^^^^^^^

• Fix default hashing behavior.
  Now hash mirrors the value of cmp and classes are unhashable by default.
  136_
  142 <https://github.com/python-attrs/attrs/issues/142>_
• Added attr.evolve() that, given an instance of an attrs class and field changes as keyword arguments, will instantiate a copy of the given instance with the changes applied.
  evolve() replaces assoc(), which is now deprecated.
  evolve() is significantly faster than assoc(), and requires the class have an initializer that can take the field values as keyword arguments (like attrs itself can generate).
  116 <https://github.com/python-attrs/attrs/issues/116>_
  124 <https://github.com/python-attrs/attrs/pull/124>_
  135 <https://github.com/python-attrs/attrs/pull/135>_
• FrozenInstanceError is now raised when trying to delete an attribute from a frozen class.
  118 <https://github.com/python-attrs/attrs/pull/118>_
• Frozen-ness of classes is now inherited.
  128 <https://github.com/python-attrs/attrs/pull/128>_
• __attrs_post_init__() is now run if validation is disabled.
  130 <https://github.com/python-attrs/attrs/pull/130>_
• Added attr.validators.in_(options) that, given the allowed options, checks whether the attribute value is in it.
  This can be used to check constants, enums, mappings, etc.
  181 <https://github.com/python-attrs/attrs/pull/181>_
• Added attr.validators.and_() that composes multiple validators into one.
  161 <https://github.com/python-attrs/attrs/issues/161>_
• For convenience, the validator argument of attr.s now can take a list of validators that are wrapped using and_().
  138 <https://github.com/python-attrs/attrs/issues/138>_
• Accordingly, attr.validators.optional() now can take a list of validators too.
  161 <https://github.com/python-attrs/attrs/issues/161>_
• Validators can now be defined conveniently inline by using the attribute as a decorator.
  Check out the examples <http://www.attrs.org/en/stable/examples.htmlvalidators>_ to see it in action!
  143 <https://github.com/python-attrs/attrs/issues/143>_
• attr.Factory() now has a takes_self argument that makes the initializer to pass the partially initialized instance into the factory.
  In other words you can define attribute defaults based on other attributes.
  165_
  189 <https://github.com/python-attrs/attrs/issues/189>_
• Default factories can now also be defined inline using decorators.
  They are always passed the partially initialized instance.
  165_
• Conversion can now be made optional using attr.converters.optional().
  105 <https://github.com/python-attrs/attrs/issues/105>_
  173 <https://github.com/python-attrs/attrs/pull/173>_
• attr.make_class() now accepts the keyword argument bases which allows for subclassing.
  152 <https://github.com/python-attrs/attrs/pull/152>_
• Metaclasses are now preserved with slots=True.
  155 <https://github.com/python-attrs/attrs/pull/155>_

.. _136: python-attrs/attrs#136
.. _165: python-attrs/attrs#165

---

16.3.0

---

Changes:
^^^^^^^^

• Attributes now can have user-defined metadata which greatly improves attrs's extensibility.
  96 <https://github.com/python-attrs/attrs/pull/96>_
• Allow for a __attrs_post_init__() method that -- if defined -- will get called at the end of the attrs-generated __init__() method.
  111 <https://github.com/python-attrs/attrs/pull/111>_
• Added attr.s(str=True) that will optionally create a __str__() method that is identical to __repr__().
  This is mainly useful with Exception\ s and other classes that rely on a useful __str__() implementation but overwrite the default one through a poor own one.
  Default Python class behavior is to use __repr__() as __str__() anyways.

If you tried using attrs with Exception\ s and were puzzled by the tracebacks: this option is for you.

• __name__ is not overwritten with __qualname__ for attr.s(slots=True) classes anymore.
  99 <https://github.com/python-attrs/attrs/issues/99>_

---

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖

[pyup-bot]

Closing this in favor of #125