[issue36457] functools.singledispatchmethod interacts poorly with subclasses
Change by Tim Mitchell : Added file: https://bugs.python.org/file50689/test_sdm.py ___ Python tracker <https://bugs.python.org/issue36457> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue36457] functools.singledispatchmethod interacts poorly with subclasses
Tim Mitchell added the comment: I've come up with a version that does not require a base class. Seems a bit hacky as the descriptor __get__ method now modifies the class to put the dispatch table in place the first time the method is accessed. -- Added file: https://bugs.python.org/file50688/singledispatchmethod.py ___ Python tracker <https://bugs.python.org/issue36457> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue36744] functools.singledispatch: Shouldn't require a positional argument if there is only one keyword argument
Tim Mitchell added the comment: I would really prefer the dispatch logic remains simple and fast, rather than handle single keyword arguments. -- nosy: +Tim Mitchell2 ___ Python tracker <https://bugs.python.org/issue36744> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue36457] functools.singledispatchmethod interacts poorly with subclasses
Tim Mitchell added the comment: Attached is an improved implementation that does not use a module level register() function. It makes the code in the original post work as expected: The `@BaseVisitor.visit.register()` decorator on the `AVisitor` class does not modify the base class dispatch table. This works by constructing the dispatch registry in the `__init_subclass__` method instead. -- Added file: https://bugs.python.org/file48261/singledispatchmethod.py ___ Python tracker <https://bugs.python.org/issue36457> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue36457] functools.singledispatchmethod interacts poorly with subclasses
New submission from Tim Mitchell :
The new functools.singledispatchmethod (issue32380) class interacts poorly with
subclasses.
There is no way for a sub-class to override or extend the dispatch registry.
E.g.
class BaseVistor:
@singledispatchmethod
def visit(self, obj):
raise ValueError('Explict vistor implementation missing)
class AVisitor(BaseVisitor):
# problem: here we can only register against base class method
@BaseVistor.visit.reister(int)
def visit_int(self, obj):
print ('integer')
The AVistor class has now changed the dispatch registry for BaseVistor class
which is bad.
To fix this the dispatch registry needs to be copied for each subclass and an
alternate register mechanism provided for subclasses to register against a
subclass method.
See attached file and pypi methoddispatch for details :)
--
components: Library (Lib)
files: methoddispatch36.py
messages: 339008
nosy: Tim Mitchell2, inada.naoki
priority: normal
severity: normal
status: open
title: functools.singledispatchmethod interacts poorly with subclasses
type: behavior
versions: Python 3.8
Added file: https://bugs.python.org/file48235/methoddispatch36.py
___
Python tracker
<https://bugs.python.org/issue36457>
___
___
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue26240] Docstring of the subprocess module should be cleaned up
Tim Mitchell added the comment: Changes as per Martins review. -- Added file: http://bugs.python.org/file45159/subprocess3.patch ___ Python tracker <http://bugs.python.org/issue26240> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue26240] Docstring of the subprocess module should be cleaned up
Tim Mitchell added the comment: Am now working from tip of default in mercurial (Python 3.6). * Removed all changes to subprocess.rst. subprocess.__doc__ * Trimmed down even further - removed function signatures. * added note to see Python docs for complete description. Exception docs * just list attributes rather than describing them - they are pretty self-explanatory. Popen.__doc__ * Trimmed down to just list arguments with 1 or 2 liner descriptions. * Added note to see Python docs for complete description. * added encoding and errors arguments -- Added file: http://bugs.python.org/file45140/subprocess2.patch ___ Python tracker <http://bugs.python.org/issue26240> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue26240] Docstring of the subprocess module should be cleaned up
Tim Mitchell added the comment: hg patch with changes forthcoming -- ___ Python tracker <http://bugs.python.org/issue26240> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue26240] Docstring of the subprocess module should be cleaned up
Tim Mitchell added the comment: Have stripped down the module __doc__ to a list of contents. I chose to indent the descriptions of each argument to Popen. I know this is non-standard but it is such a long ramble otherwise. Changed true -> :const:`True` in subprocess.rst. -- keywords: +patch nosy: +tim.mitchell Added file: http://bugs.python.org/file45126/subprocess-docs.patch ___ Python tracker <http://bugs.python.org/issue26240> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue27946] issues in elementtree and elsewhere due to PyDict_GetItem
Tim Mitchell added the comment: Added test to patch -- ___ Python tracker <http://bugs.python.org/issue27946> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue27946] issues in elementtree and elsewhere due to PyDict_GetItem
Changes by Tim Mitchell : Removed file: http://bugs.python.org/file44605/0001-issue27946-Hold-reference-to-dict-in-PyDict_GetItem.patch ___ Python tracker <http://bugs.python.org/issue27946> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue27946] issues in elementtree and elsewhere due to PyDict_GetItem
Changes by Tim Mitchell : Added file: http://bugs.python.org/file44611/0001-issue27946-Hold-reference-to-dict-in-PyDict_GetItem.patch ___ Python tracker <http://bugs.python.org/issue27946> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue27946] issues in elementtree and elsewhere due to PyDict_GetItem
Tim Mitchell added the comment: see also similar dict issue 27945 -- ___ Python tracker <http://bugs.python.org/issue27946> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue27946] issues in elementtree and elsewhere due to PyDict_GetItem
Tim Mitchell added the comment: see also similar dict issue 27945 -- ___ Python tracker <http://bugs.python.org/issue27946> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue27946] issues in elementtree and elsewhere due to PyDict_GetItem
Tim Mitchell added the comment: Verified problem. Added patch to keep reference to dict in PyDict_GetItem. -- keywords: +patch nosy: +Tim Mitchell Added file: http://bugs.python.org/file44605/0001-issue27946-Hold-reference-to-dict-in-PyDict_GetItem.patch ___ Python tracker <http://bugs.python.org/issue27946> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue27945] Various segfaults with dict
Tim Mitchell added the comment: Here is my patch for parts 3 and 4. Core issue for part 4 appears to be dk_lookup calling arbitrary python code may free the key. dk_lookup is also used in _PyDict_LoadGlobal not sure if this bug can occur here. -- nosy: +Tim Mitchell Added file: http://bugs.python.org/file44587/0001-Issue-27945-Fixed-segfaults-in-dict.fromkeys-when-it.patch ___ Python tracker <http://bugs.python.org/issue27945> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
