[issue16382] Better warnings exception for bad category
Roundup Robot added the comment: New changeset c4a86fe52006 by Berker Peksag in branch 'default': Issue #16382: Improve exception message of warnings.warn() for bad category. http://hg.python.org/cpython/rev/c4a86fe52006 -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16382] Better warnings exception for bad category
Berker Peksag added the comment: Thanks for the patch, Phil. -- assignee: - berker.peksag nosy: +r.david.murray resolution: - fixed stage: patch review - resolved status: open - closed type: behavior - enhancement ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16382] Better warnings exception for bad category
Berker Peksag added the comment: Here's a new patch addressing Ezio's Rietveld comment. I've also used assertRaisesRegex instead of assertRaises in tests. -- nosy: +berker.peksag Added file: http://bugs.python.org/file35772/issue16382_v5.diff ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16382] Better warnings exception for bad category
Changes by Berker Peksag berker.pek...@gmail.com: -- versions: +Python 3.5 -Python 3.4 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16382] Better warnings exception for bad category
Phil Elson added the comment: Ok. I think I've done all of the actions from the reviews. I'm not sure if I should remove the old patches or not? Thanks, -- Added file: http://bugs.python.org/file29304/pelson_warnings_fix_4.diff ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16382] Better warnings exception for bad category
Changes by Phil Elson pelson@gmail.com: Added file: http://bugs.python.org/file28072/pelson_warnings_fix_3.diff ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16382] Better warnings exception for bad category
Changes by Phil Elson pelson@gmail.com: Added file: http://bugs.python.org/file28053/pelson_warnings_fix_2.diff ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16382] Better warnings exception for bad category
Changes by Ezio Melotti ezio.melo...@gmail.com: -- nosy: +ezio.melotti stage: - patch review ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue16382] Better warnings exception for bad category
New submission from Phil Elson:
When passing an invalid Warning subclasses to the warnings.warn function, a
bare issubclass exception is raised:
import warnings
warnings.warn('hello world', 'not a valid warning type')
Traceback (most recent call last):
File stdin, line 1, in module
TypeError: issubclass() arg 1 must be a class
This exception is consistent accross both Python/_warnings.c and
Lib/warnings.py implementations, but I feel it could be more helpful/explicit
about the nature problem.
To test both cases I have been using the following code (python3.4):
import test.support
py_warnings = test.warnings = test.support.import_fresh_module('warnings',
blocked=['_warnings'])
c_warnings = test.support.import_fresh_module('warnings',
fresh=['_warnings'])
Now:
py_warnings.warn('hello world', '')
Traceback (most recent call last):
File stdin, line 1, in module
File lib/python3.4/warnings.py, line 168, in warn
assert issubclass(category, Warning)
TypeError: issubclass() arg 1 must be a class
c_warnings.warn('hello world', '')
Traceback (most recent call last):
File stdin, line 1, in module
TypeError: issubclass() arg 1 must be a class
Additionally, there is a difference in the denotational semantics of None
between the c and py warnings implementation:
py_warnings.warn('Hello world', None)
__main__:1: UserWarning: Hello world
c_warnings.warn('Hello world', None)
Traceback (most recent call last):
File stdin, line 1, in module
TypeError: issubclass() arg 1 must be a class
I can understand that python does not allow the concept of an optional
positional arguments and therefore it is arguable that the signatures of the
two functions are inevitably going to be different. I defer to someone more
knowledgeable in Python to decide if this is a problem, and whether it should
be made consistent.
Attached is a patch to address these two issues, with associated tests. Please
review (n.b. I am a python developer at heart, and only dabble in C when I have
to, so extra scrutiny on the C would be valuable to me) and I'd be happy to get
any necessary changed applied to the patch asap.
In short, as a result of applying this patch, the following results ensue:
py_warnings.warn('hello world', '')
Traceback (most recent call last):
File stdin, line 1, in module
File lib/python3.4/warnings.py, line 175, in warn
'Got {!r}'.format(Warning, category)) from None
ValueError: category must be a subclass of class 'Warning'.Got ''
c_warnings.warn('hello world', '')
Traceback (most recent call last):
File stdin, line 1, in module
ValueError: category must be a subclass of class 'Warning'. Got ''.
c_warnings.warn('hello world', None)
__main__:1: UserWarning: hello world
Thanks!
--
components: Library (Lib)
files: pelson_warnings_fix.diff
keywords: patch
messages: 174421
nosy: pelson
priority: normal
severity: normal
status: open
title: Better warnings exception for bad category
type: behavior
versions: Python 3.4
Added file: http://bugs.python.org/file27824/pelson_warnings_fix.diff
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[issue16382] Better warnings exception for bad category
Changes by Antoine Pitrou pit...@free.fr: -- nosy: +brett.cannon ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16382 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
