Issue 25926: Clarify that the itertools pure python equivalents are only approximate. (original) (raw)
Created on 2015-12-22 17:40 by tfeldmann, last changed 2022-04-11 14:58 by admin. This issue is now closed.
Messages (10)
Author: Thomas Feldmann (tfeldmann)
Date: 2015-12-22 17:40
According to the docs itertools.repeat(object[, times]) is equivalent to
def repeat(object, times=None):
# repeat(10, 3) --> 10 10 10
if times is None:
while True:
yield object
else:
for i in range(times):
yield objectBut it raises a TypeError when used this way:
Python 3.5.1 (default, Dec 10 2015, 10:34:07)
[GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.1.76)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from itertools import repeat
>>> repeat('x', times=None)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'NoneType' object cannot be interpreted as an integerThe times keyword can be omitted but not explicitly set to None.
I checked with Python Versions 2.7 and 3.5.1 on Mac OS X and Windows 10.
Author: R. David Murray (r.david.murray) * 
Date: 2015-12-22 17:46
Huh. I always thought the wording was "roughly equivalent to". This is a consequence of C vs python, and is the reason the docstring uses the [] notation.
Author: Camilla Montonen (Winterflower)
Date: 2016-05-18 20:11
Should 'roughly equivalent to' be added as a note to the docs?
Author: Raymond Hettinger (rhettinger) *
Date: 2016-05-19 01:17
I'm okay with changing the docs to "roughly equivalent to". That will help prevent the occasional misreading as "precisely equivalent in every respect".
Author: Nofar Schnider (Nofar Schnider) * 
Date: 2016-05-27 06:00
Issue #25926 Changed all "equivalent to" occurrences to "roughly equivalent to"
Author: Nofar Schnider (Nofar Schnider) *
Date: 2016-05-27 06:11
Attached a diff All occurrences of "equivalent to" are switched to "roughly equivalent to"
Author: Roundup Robot (python-dev)
Date: 2016-05-28 07:18
New changeset 613314c3f9ed by Raymond Hettinger in branch '3.5': Issue 25926: Clarify that the pure python equivalents are only approximate. https://hg.python.org/cpython/rev/613314c3f9ed
New changeset e67e970de54a by Raymond Hettinger in branch 'default': Issue 25926: Clarify that the pure python equivalents are only approximate. https://hg.python.org/cpython/rev/e67e970de54a
Author: Roundup Robot (python-dev)
Date: 2016-05-28 07:26
New changeset f66c30f66235 by Raymond Hettinger in branch '2.7': Issue 25926: Clarify that the pure python equivalents are only approximate. https://hg.python.org/cpython/rev/f66c30f66235
Author: Raymond Hettinger (rhettinger) *
Date: 2016-05-28 07:27
Nofar, thanks for the patch.
Author: Roundup Robot (python-dev)
Date: 2016-05-28 11:26
New changeset 35fa2ec1f237 by Serhiy Storchaka in branch 'default': Merge heads (issue #25926). https://hg.python.org/cpython/rev/35fa2ec1f237
History
Date
User
Action
Args
2022-04-11 14:58:25
admin
set
github: 70114
2016-05-28 11:26:07
python-dev
set
messages: +
2016-05-28 07:27:44
rhettinger
set
status: open -> closed
title: problems with "times" keyword in itertools.repeat -> Clarify that the itertools pure python equivalents are only approximate.
messages: +
components: + Documentation, - Interpreter Core
resolution: fixed
2016-05-28 07:26:51
python-dev
set
messages: +
2016-05-28 07🔞42
python-dev
set
nosy: + python-dev
messages: +
2016-05-27 06:11:02
Nofar Schnider
set
files: + issue25926.diff
hgrepos: + hgrepo345
messages: +
keywords: + patch
2016-05-27 06:07:06
Nofar Schnider
set
files: - itertools.rst
2016-05-27 06:00:45
Nofar Schnider
set
files: + itertools.rst
nosy: + Nofar Schnider
messages: +
hgrepos: + hgrepo344
2016-05-19 01:17:50
rhettinger
set
priority: normal -> low
messages: +
2016-05-18 20:17:00
serhiy.storchaka
set
assignee: rhettinger
2016-05-18 20:11:31
Winterflower
set
nosy: + Winterflower
messages: +
2015-12-22 17:46:32
r.david.murray
set
nosy: + rhettinger, r.david.murray
messages: +
2015-12-22 17:40:36
tfeldmann
create