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slots=True do not play nice with __init_subclass__ #269

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malinoff opened this issue Oct 17, 2017 · 6 comments
Closed

slots=True do not play nice with __init_subclass__ #269

malinoff opened this issue Oct 17, 2017 · 6 comments
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@malinoff
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A class annotated with attr.s(slots=True) can't call super().__init__subclass__ within its own __init_subclass__ method - a TypeError: super(type, obj): obj must be an instance or subtype of type is raised.

Reproducible example (tested on 16.3.0, 17.2.0 and f7f53d4) is here: https://repl.it/Mmkb/0

@hynek hynek added this to the 17.3 milestone Oct 17, 2017
@hynek
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hynek commented Oct 17, 2017

Uh is that another thing with cells? Is it fixable? And more importantly, is this something we’re breaking with #260 for dict classes too? :|

@Tinche
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Tinche commented Oct 17, 2017

I'll take a look. This is a PEP 487 thing I see, Python 3.6+.

@Tinche
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Tinche commented Oct 17, 2017

It's fixable. I can push a commit to the replace-class branch a little later.

@Tinche
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Tinche commented Oct 17, 2017

So I'm sitting here trying to write a test for this and for some reason, the test I've written is passing even when I comment out the fix.

Turns out CPython will actually reuse closure cells sometimes. So if a class has a normal method that needs to be rewritten, the problem will not manifest. 😱

@hynek
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hynek commented Oct 20, 2017

JFTR @malinoff, you prevented us from making a huge mistake and release it – in the last minute! So many thanks for that!

@malinoff
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@hynek my pleasure!

bors-fusion bot added a commit to fusionapp/fusion-index that referenced this issue Nov 15, 2017
167: Scheduled weekly dependency update for week 46 r=mithrandi




## Updates
Here's a list of all the updates bundled in this pull request. I've added some links to make it easier for you to find all the information you need.
<table align="center">

<tr>
<td><b>attrs</b></td>
<td align="center">17.2.0</td>
<td align="center">&raquo;</td>
<td align="center">17.3.0</td>
<td>
     <a href="https://pypi.python.org/pypi/attrs">PyPI</a> | <a href="https://pyup.io/changelogs/attrs/">Changelog</a> | <a href="http://www.attrs.org/">Homepage</a> 

</td>

<tr>
<td><b>cryptography</b></td>
<td align="center">2.1.2</td>
<td align="center">&raquo;</td>
<td align="center">2.1.3</td>
<td>
     <a href="https://pypi.python.org/pypi/cryptography">PyPI</a> | <a href="https://pyup.io/changelogs/cryptography/">Changelog</a> | <a href="https://github.com/pyca/cryptography">Repo</a> 

</td>

<tr>
<td><b>hypothesis</b></td>
<td align="center">3.33.0</td>
<td align="center">&raquo;</td>
<td align="center">3.37.0</td>
<td>
     <a href="https://pypi.python.org/pypi/hypothesis">PyPI</a> | <a href="https://pyup.io/changelogs/hypothesis/">Changelog</a> | <a href="https://github.com/HypothesisWorks/hypothesis/issues">Repo</a> 

</td>

</tr>
</table>



## Changelogs


### attrs 17.2.0 -> 17.3.0

>### 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 &lt;https://github.com/python-attrs/attrs/issues/253&gt;`_)


>Changes
>^^^^^^^

>- ``super()`` and ``__class__`` now work on Python 3 when ``slots=True``.
>  (`102 &lt;https://github.com/python-attrs/attrs/issues/102&gt;`_, `226 &lt;https://github.com/python-attrs/attrs/issues/226&gt;`_, `269 &lt;https://github.com/python-attrs/attrs/issues/269&gt;`_, `270 &lt;https://github.com/python-attrs/attrs/issues/270&gt;`_, `272 &lt;https://github.com/python-attrs/attrs/issues/272&gt;`_)
>- 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 &lt;https://www.python.org/dev/peps/pep-0526/&gt;`_). (`151 &lt;https://github.com/python-attrs/attrs/issues/151&gt;`_, `214 &lt;https://github.com/python-attrs/attrs/issues/214&gt;`_, `215 &lt;https://github.com/python-attrs/attrs/issues/215&gt;`_, `239 &lt;https://github.com/python-attrs/attrs/issues/239&gt;`_)
>- The combination of ``str=True`` and ``slots=True`` now works on Python 2.
>  (`198 &lt;https://github.com/python-attrs/attrs/issues/198&gt;`_)
>- ``attr.Factory`` is hashable again. (`204
>  &lt;https://github.com/python-attrs/attrs/issues/204&gt;`_)
>- 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 &lt;https://github.com/python-attrs/attrs/issues/221&gt;`_, `229 &lt;https://github.com/python-attrs/attrs/issues/229&gt;`_)
>- 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 &lt;https://github.com/python-attrs/attrs/issues/262&gt;`_, `277 &lt;https://github.com/python-attrs/attrs/issues/277&gt;`_)
>- Instances of classes created using ``attr.make_class()`` can now be pickled.
>  (`282 &lt;https://github.com/python-attrs/attrs/issues/282&gt;`_)


>----








### hypothesis 3.33.0 -> 3.37.0

>### 3.37.0

>-------------------

>This is a deprecation release for some health check related features.

>The following are now deprecated:

>* Passing :attr:`~hypothesis.HealthCheck.exception_in_generation` to
>  :attr:`~hypothesis.settings.suppress_health_check`. This no longer does
>  anything even when passed -  All errors that occur during data generation
>  will now be immediately reraised rather than going through the health check
>  mechanism.
>* Passing :attr:`~hypothesis.HealthCheck.random_module` to
>  :attr:`~hypothesis.settings.suppress_health_check`. This hasn&#39;t done anything
>  for a long time, but was never explicitly deprecated. Hypothesis always seeds
>  the random module when running given tests, so this is no longer an error
>  and suppressing it doesn&#39;t do anything.
>* Passing non-:class:`~hypothesis.HealthCheck` values in
>  :attr:`~hypothesis.settings.suppress_health_check`. This was previously
>  allowed but never did anything useful.

>In addition, passing a non-iterable value as :attr:`~hypothesis.settings.suppress_health_check`
>will now raise an error immediately (it would never have worked correctly, but
>it would previously have failed later). Some validation error messages have
>also been updated.

>This work was funded by `Smarkets &lt;https://smarkets.com/&gt;`_.

>-------------------


>### 3.36.1

>-------------------

>This is a yak shaving release, mostly concerned with our own tests.

>While :func:`~python:inspect.getfullargspec` was documented as deprecated
>in Python 3.5, it never actually emitted a warning.  Our code to silence
>this (nonexistent) warning has therefore been removed.

>We now run our tests with ``DeprecationWarning`` as an error, and made some
>minor changes to our own tests as a result.  This required similar upstream
>updates to :pypi:`coverage` and :pypi:`execnet` (a test-time dependency via
>:pypi:`pytest-xdist`).

>There is no user-visible change in Hypothesis itself, but we encourage you
>to consider enabling deprecations as errors in your own tests.

>-------------------


>### 3.36.0

>-------------------

>This release adds a setting to the public API, and does some internal cleanup:

>- The :attr:`~hypothesis.settings.derandomize` setting is now documented (:issue:`890`)
>- Removed - and disallowed - all &#39;bare excepts&#39; in Hypothesis (:issue:`953`)
>- Documented the :attr:`~hypothesis.settings.strict` setting as deprecated, and
>  updated the build so our docs always match deprecations in the code.

>-------------------


>### 3.35.0

>-------------------

>This minor release supports constraining :func:`~hypothesis.strategies.uuids`
>to generate :class:`~python:uuid.UUID`s of a particular version.
>(:issue:`721`)

>Thanks to Dion Misic for this feature.

>-------------------


>### 3.34.1

>-------------------

>This patch updates the documentation to suggest
>:func:`builds(callable) &lt;hypothesis.strategies.builds&gt;` instead of
>:func:`just(callable()) &lt;hypothesis.strategies.just&gt;`.

>-------------------


>### 3.34.0

>-------------------

>Hypothesis now emits deprecation warnings if you apply
>:func:`given &lt;hypothesis.given&gt;` more than once to a target.

>Applying :func:`given &lt;hypothesis.given&gt;` repeatedly wraps the target multiple
>times. Each wrapper will search the space of of possible parameters separately.
>This is equivalent but will be much more inefficient than doing it with a
>single call to :func:`given &lt;hypothesis.given&gt;`.

>For example, instead of
>``given(booleans()) given(integers())``, you could write
>``given(booleans(), integers())``

>-------------------


>### 3.33.1

>-------------------

>This is a bugfix release:

>- :func:`~hypothesis.strategies.builds` would try to infer a strategy for
>  required positional arguments of the target from type hints, even if they
>  had been given to :func:`~hypothesis.strategies.builds` as positional
>  arguments (:issue:`946`).  Now it only infers missing required arguments.
>- An internal introspection function wrongly reported ``self`` as a required
>  argument for bound methods, which might also have affected
>  :func:`~hypothesis.strategies.builds`.  Now it knows better.

>-------------------









That's it for now!

Happy merging! 🤖
bors-fusion bot added a commit to fusionapp/entropy that referenced this issue Nov 15, 2017
161: Scheduled weekly dependency update for week 46 r=mithrandi




## Updates
Here's a list of all the updates bundled in this pull request. I've added some links to make it easier for you to find all the information you need.
<table align="center">

<tr>
<td><b>attrs</b></td>
<td align="center">17.2.0</td>
<td align="center">&raquo;</td>
<td align="center">17.3.0</td>
<td>
     <a href="https://pypi.python.org/pypi/attrs">PyPI</a> | <a href="https://pyup.io/changelogs/attrs/">Changelog</a> | <a href="http://www.attrs.org/">Homepage</a> 

</td>

<tr>
<td><b>cryptography</b></td>
<td align="center">2.1.2</td>
<td align="center">&raquo;</td>
<td align="center">2.1.3</td>
<td>
     <a href="https://pypi.python.org/pypi/cryptography">PyPI</a> | <a href="https://pyup.io/changelogs/cryptography/">Changelog</a> | <a href="https://github.com/pyca/cryptography">Repo</a> 

</td>

<tr>
<td><b>lxml</b></td>
<td align="center">4.1.0</td>
<td align="center">&raquo;</td>
<td align="center">4.1.1</td>
<td>
     <a href="https://pypi.python.org/pypi/lxml">PyPI</a> | <a href="https://pyup.io/changelogs/lxml/">Changelog</a> | <a href="http://lxml.de/">Homepage</a> | <a href="https://bugs.launchpad.net/lxml">Bugtracker</a> 

</td>

<tr>
<td><b>pytz</b></td>
<td align="center">2017.2</td>
<td align="center">&raquo;</td>
<td align="center">2017.3</td>
<td>
     <a href="https://pypi.python.org/pypi/pytz">PyPI</a> | <a href="http://pythonhosted.org/pytz">Homepage</a> | <a href="http://pythonhosted.org/pytz/">Docs</a> 

</td>

</tr>
</table>



## Changelogs


### attrs 17.2.0 -> 17.3.0

>### 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 &lt;https://github.com/python-attrs/attrs/issues/253&gt;`_)


>Changes
>^^^^^^^

>- ``super()`` and ``__class__`` now work on Python 3 when ``slots=True``.
>  (`102 &lt;https://github.com/python-attrs/attrs/issues/102&gt;`_, `226 &lt;https://github.com/python-attrs/attrs/issues/226&gt;`_, `269 &lt;https://github.com/python-attrs/attrs/issues/269&gt;`_, `270 &lt;https://github.com/python-attrs/attrs/issues/270&gt;`_, `272 &lt;https://github.com/python-attrs/attrs/issues/272&gt;`_)
>- 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 &lt;https://www.python.org/dev/peps/pep-0526/&gt;`_). (`151 &lt;https://github.com/python-attrs/attrs/issues/151&gt;`_, `214 &lt;https://github.com/python-attrs/attrs/issues/214&gt;`_, `215 &lt;https://github.com/python-attrs/attrs/issues/215&gt;`_, `239 &lt;https://github.com/python-attrs/attrs/issues/239&gt;`_)
>- The combination of ``str=True`` and ``slots=True`` now works on Python 2.
>  (`198 &lt;https://github.com/python-attrs/attrs/issues/198&gt;`_)
>- ``attr.Factory`` is hashable again. (`204
>  &lt;https://github.com/python-attrs/attrs/issues/204&gt;`_)
>- 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 &lt;https://github.com/python-attrs/attrs/issues/221&gt;`_, `229 &lt;https://github.com/python-attrs/attrs/issues/229&gt;`_)
>- 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 &lt;https://github.com/python-attrs/attrs/issues/262&gt;`_, `277 &lt;https://github.com/python-attrs/attrs/issues/277&gt;`_)
>- Instances of classes created using ``attr.make_class()`` can now be pickled.
>  (`282 &lt;https://github.com/python-attrs/attrs/issues/282&gt;`_)


>----








### lxml 4.1.0 -> 4.1.1

>### 4.1.1

>==================

>* Rebuild with Cython 0.27.3 to improve support for Py3.7.











That's it for now!

Happy merging! 🤖
bors-fusion bot added a commit to fusionapp/documint that referenced this issue Nov 17, 2017
118: Update attrs to 17.3.0 r=mithrandi


There's a new version of [attrs](https://pypi.python.org/pypi/attrs) available.
You are currently using **17.2.0**. I have updated it to **17.3.0**



These links might come in handy:  <a href="https://pypi.python.org/pypi/attrs">PyPI</a> | <a href="https://pyup.io/changelogs/attrs/">Changelog</a> | <a href="http://www.attrs.org/">Homepage</a> 



### Changelog
> 
>### 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 &lt;https://github.com/python-attrs/attrs/issues/253&gt;`_)


>Changes
>^^^^^^^

>- ``super()`` and ``__class__`` now work on Python 3 when ``slots=True``.
>  (`102 &lt;https://github.com/python-attrs/attrs/issues/102&gt;`_, `226 &lt;https://github.com/python-attrs/attrs/issues/226&gt;`_, `269 &lt;https://github.com/python-attrs/attrs/issues/269&gt;`_, `270 &lt;https://github.com/python-attrs/attrs/issues/270&gt;`_, `272 &lt;https://github.com/python-attrs/attrs/issues/272&gt;`_)
>- 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 &lt;https://www.python.org/dev/peps/pep-0526/&gt;`_). (`151 &lt;https://github.com/python-attrs/attrs/issues/151&gt;`_, `214 &lt;https://github.com/python-attrs/attrs/issues/214&gt;`_, `215 &lt;https://github.com/python-attrs/attrs/issues/215&gt;`_, `239 &lt;https://github.com/python-attrs/attrs/issues/239&gt;`_)
>- The combination of ``str=True`` and ``slots=True`` now works on Python 2.
>  (`198 &lt;https://github.com/python-attrs/attrs/issues/198&gt;`_)
>- ``attr.Factory`` is hashable again. (`204
>  &lt;https://github.com/python-attrs/attrs/issues/204&gt;`_)
>- 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 &lt;https://github.com/python-attrs/attrs/issues/221&gt;`_, `229 &lt;https://github.com/python-attrs/attrs/issues/229&gt;`_)
>- 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 &lt;https://github.com/python-attrs/attrs/issues/262&gt;`_, `277 &lt;https://github.com/python-attrs/attrs/issues/277&gt;`_)
>- Instances of classes created using ``attr.make_class()`` can now be pickled.
>  (`282 &lt;https://github.com/python-attrs/attrs/issues/282&gt;`_)


>----








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

Happy merging! 🤖
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