Mailman 3 March 2018 - docs

[issue24045] Behavior of large returncodes (sys.exit(nn))
by Ethan Furman 26 Feb '21

26 Feb '21

New submission from Ethan Furman: Not sure if this is a bug, or just One of Those Things: sys.exit(large_value) can wrap around if the value is too large, but this is O/S dependent. linux (ubuntu 14.04) $ python Python 2.7.8 (default, Oct 20 2014, 15:05:29) [GCC 4.9.1] on linux2 Type "help", "copyright", "credits" or "license" for more information. --> import sys --> sys.exit(256) $ echo $? 0 $ python Python 2.7.8 (default, Oct 20 2014, 15:05:29) [GCC 4.9.1] on linux2 Type "help", "copyright", "credits" or "license" for more information. --> import sys --> sys.exit(257) $ echo $? 1 M$ (Windows 7) > python Python 2.7... --> import sys --> sys.exit(65535) > echo %errorlevel% 65535 > python Python 2.7... --> import sys --> sys.exit(100000) > echo %errorlevel% 100000 Perhaps a minor doc update that talks about return codes and why they might not be exactly what was given to Python? ---------- assignee: docs@python messages: 241903 nosy: docs@python, ethan.furman priority: normal severity: normal status: open title: Behavior of large returncodes (sys.exit(nn)) versions: Python 2.7, Python 3.5 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue24045> _______________________________________

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[issue13368] Possible problem in documentation of module subprocess, method send_signal
by Eli Bendersky 24 Feb '21

24 Feb '21

New submission from Eli Bendersky <eliben(a)gmail.com>: docs@ list report by Daniel Dieterle: in the documentation (http://docs.python.org/library/subprocess.html#subprocess.Popen.send_signal) is a bug. CTRL_C_EVENT can not be sent to processes started with a creationflags parameter which includes CREATE_NEW_PROCESS_GROUP. Why can be read in the msdn documentation http://msdn.microsoft.com/en-us/library/windows/desktop/ms683155%28v=vs.85%… . A workaround using CTRL_C_EVENT nevertheless is described here: http://stackoverflow.com/questions/7085604/sending-c-to-python-subprocess-o… -- I do not know why the subprocess.CREATE_NEW_PROCESS_GROUP parameter was introduced. But it is useless for terminating a process with os.kill() in combination with signal.SIGTERM, which corresponds to a CTRL-C-EVENT. A CTRL-C-EVENT is only forwarded to the process if the process group is zero. Therefore the Note in the documentation on Popen.send_signal() is wrong. ---------- assignee: docs@python components: Documentation messages: 147272 nosy: docs@python, eli.bendersky priority: normal severity: normal status: open title: Possible problem in documentation of module subprocess, method send_signal versions: Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue13368> _______________________________________

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[issue16954] Add docstrings for ElementTree module
by Serhiy Storchaka 21 Feb '21

21 Feb '21

New submission from Serhiy Storchaka: Perhaps almost all Doxygen comments in ElementTree module should be converted to docstrings. ---------- assignee: docs@python components: Documentation, XML messages: 179881 nosy: docs@python, eli.bendersky, serhiy.storchaka priority: normal severity: normal stage: needs patch status: open title: Add docstrings for ElementTree module type: enhancement versions: Python 3.4 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue16954> _______________________________________

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[issue27646] yield from expression can be any iterable
by Terry J. Reedy 21 Feb '21

21 Feb '21

New submission from Terry J. Reedy: https://docs.python.org/3/reference/expressions.html#yield-expressions says "When yield from <expr> is used, it treats the supplied expression as a subiterator. All values produced by that subiterator ...". To me "treats..expression as a subiterator" means that the expression must *be* an iterator, such as returned by iter or calling a generator function. Hence I was surprised upon reading "yield from <non-iterator iterable>" in stdlib code. I confirmed that this usage is correct by trying >>> def g(): yield from (1,2) >>> i = g() >>> next(i), next(i) (1, 2) and then reading the PEP380 Formal Semantics, which begins with "_i = iter(EXPR)". Hence I suggest the following replacement for the quote above: "When yield from <expr> is used, the expression must be an iterable. A subiterator is obtained with iter(<expr>). All values produced by that subiterator ...". Note that 'subiterator' is spelled in the following sentences 'underlying iterable' (which I am not sure I like) and 'sub-iterator' (and 'sub-generator'). I think we should be consistent for at least the two short 'yield from' paragraphs. ---------- assignee: docs@python components: Documentation messages: 271577 nosy: docs@python, terry.reedy priority: normal severity: normal stage: patch review status: open title: yield from expression can be any iterable type: behavior versions: Python 3.5, Python 3.6 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue27646> _______________________________________

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[issue13433] String format documentation contains error regarding %g
by Christian Iversen 18 Feb '21

18 Feb '21

New submission from Christian Iversen <ci(a)sikkerhed.org>: The documentation for string format options state that both %f, %g and %e default to 6 digits after the decimal point. In fact, %g always seems to use 5 digits by default: >>> "%g" % 2.1234567 '2.12346' >>> "%f" % 2.1234567 '2.123457' >>> "%e" % 2.1234567 '2.123457e+00' But something much more insidious is wrong, because even when explicitly told how many digits to have, %g is one off: >>> "%.6g" % 2.1234567 '2.12346' >>> "%.6f" % 2.1234567 '2.123457' >>> "%.6e" % 2.1234567 '2.123457e+00' This can't be right? ---------- assignee: docs@python components: Documentation messages: 147940 nosy: Christian.Iversen, docs@python priority: normal severity: normal status: open title: String format documentation contains error regarding %g type: behavior versions: Python 2.6, Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue13433> _______________________________________

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[issue29086] Document C API that is not part of the limited API
by Serhiy Storchaka 18 Feb '21

18 Feb '21

New submission from Serhiy Storchaka: >From the documentation: https://docs.python.org/3/c-api/stable.html In the C API documentation, API elements that are not part of the limited API are marked as "Not part of the limited API." But they don't. Following sample patch adds the notes to Unicode Objects and Codecs C API. I'm going to add them to all C API. What are your though about formatting the note? Should it be before the description, after the description, but before the "deprecated" directive (as in the patch), or after the first paragraph of the description? Should it be on the separate line or be appended at the end of the previous paragraph, or starts the first paragraph (if before the description)? May be introduce a special directive for it? ---------- assignee: docs@python components: Documentation files: unicode-not-part-of-the-limited-api.patch keywords: patch messages: 284125 nosy: docs@python, georg.brandl, serhiy.storchaka priority: normal severity: normal status: open title: Document C API that is not part of the limited API type: enhancement versions: Python 3.5, Python 3.6, Python 3.7 Added file: http://bugs.python.org/file46057/unicode-not-part-of-the-limited-api.patch _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue29086> _______________________________________

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[issue20464] Update distutils sample config file in Doc/install/index.rst
by Zachary Ware 03 Feb '21

03 Feb '21

New submission from Zachary Ware: >From docs@: On Thu, Jan 16, 2014 at 2:56 AM, Peter Bröcker <peter.broecker(a)uni-koeln.de> wrote: > Hi, > > I have tried to set up the distutils config files for a custom module > installation. Using the suggested snippet from > > http://docs.python.org/2/install/ > > [install] > install-base=$HOME/python > install-purelib=lib > install-platlib=lib.$PLAT > install-scripts=scripts > install-data=data did not work for me. > > Instead, I had to add install-headers and additionally modify all paths > to include $base: > > [install] > install-base=/some/dir > install-purelib=$base/lib > install-platlib=$base/lib.$PLAT > install-scripts=$base/scripts > install-headers=$base/include > install-data=$base/data > > > I'm unsure if this is actually a bug, but I could only resolve this with > the help of this answer on stackoverflow: > http://stackoverflow.com/a/12768721 > > Best regards, > Peter ---------- assignee: docs@python components: Distutils, Documentation messages: 209829 nosy: docs@python, zach.ware priority: normal severity: normal stage: test needed status: open title: Update distutils sample config file in Doc/install/index.rst type: behavior versions: Python 2.7, Python 3.3, Python 3.4 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue20464> _______________________________________

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[issue22401] argparse: 'resolve' conflict handler damages the actions of the parent parser
by paul j3 27 Jan '21

27 Jan '21

New submission from paul j3: When there's a conflict involving an argument that was added via 'parents', and the conflict handler is 'resolve', the action in the parent parser may be damaged, rendering that parent unsuitable for further use. In this example, 2 parents have the same '--config' argument: parent1 = argparse.ArgumentParser(add_help=False) parent1.add_argument('--config') parent2 = argparse.ArgumentParser(add_help=False) parent2.add_argument('--config') parser = argparse.ArgumentParser(parents=[parent1,parent2], conflict_handler='resolve') The actions of the 3 parsers are (from the ._actions list): (id, dest, option_strings) parent1: [(3077384012L, 'config', [])] # empty option_strings parent2: [(3076863628L, 'config', ['--config'])] parser: [(3076864428L, 'help', ['-h', '--help']), (3076863628L, 'config', ['--config'])] # same id The 'config' Action from 'parent1' is first copied to 'parser' by reference (this is important). When 'config' from 'parent2' is copied, there's a conflict. '_handle_conflict_resolve()' attempts to remove the first Action, so it can add the second. But in the process it ends up deleting the 'option_strings' values from the original action. So now 'parent1' has an action in its 'optionals' argument group with an empty option_strings list. It would display as an 'optionals' but parse as a 'positionals'. 'parent1' can no longer be safely used as a parent for another (sub)parser, nor used as a parser itself. The same sort of thing would happen, if, as suggested in the documentation: "Sometimes (e.g. when using parents_) it may be useful to simply override any older arguments with the same option string." In test_argparse.py, 'resolve' is only tested once, with a simple case of two 'add_argument' statements. The 'parents' class tests a couple of cases of conflicting actions (for positionals and optionals), but does nothing with the 'resolve' handler. ------------------------------ Possible fixes: - change the documentation to warn against reusing such a parent parser - test the 'resolve' conflict handler more thoroughly - rewrite this conflict handler so it does not modify the action in the parent - possibly change the 'parents' mechanism so it does a deep copy of actions. References: http://stackoverflow.com/questions/25818651/argparse-conflict-resolver-for-… http://bugs.python.org/issue15271 argparse: repeatedly specifying the same argument ignores the previous ones http://bugs.python.org/issue19462 Add remove_argument() method to argparse.ArgumentParser http://bugs.python.org/issue15428 add "Name Collision" section to argparse docs ---------- assignee: docs@python components: Documentation, Library (Lib), Tests messages: 226862 nosy: docs@python, paul.j3 priority: normal severity: normal status: open title: argparse: 'resolve' conflict handler damages the actions of the parent parser type: behavior versions: Python 3.5 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue22401> _______________________________________

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[issue24711] Document getpass.getpass behavior on ^C
by Markus Unterwaditzer 11 Jan '21

11 Jan '21

New submission from Markus Unterwaditzer: getpass.getpass doesn't enter a newline when the user aborts input with ^C, while input/raw_input does. This behavior is surprising and can lead to mis-formatting of subsequent output. However, since this behavior exists since 2.7 and applications may have started to rely on it, I'd add a note to the documentation. ---------- assignee: docs@python components: Documentation messages: 247302 nosy: docs@python, untitaker priority: normal severity: normal status: open title: Document getpass.getpass behavior on ^C versions: Python 2.7, Python 3.2, Python 3.3, Python 3.4, Python 3.5, Python 3.6 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue24711> _______________________________________

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[issue8595] Unexpected default timeout in http-client-related libraries
by Julian 28 Dec '20

28 Dec '20

New submission from Julian <python_org(a)somethinkodd.com>: Since Python 2.6, httplib has offered a timeout parameter for fetches. As the documentation explains, if this parameter is not provided, it uses the global default. What the document doesn't explain is httplib builds on top of the socket library. The socket library has a default timeout of None (i.e. forever). This may be an appropriate default for general sockets, but it is a poor default for httplib; typical http clients would use a timeout in the 2-10 second range. This problem is propagated up to urllib2, which sits on httplib, and further obscures that the default might be unsuitable. >From an inspection of the manuals, Python 3.0.1 suffers from the same problem except, the names have changed. urllib.response sits on http.client. I, for one, made a brutal mistake of assuming that the "global default" would be some reasonable default for fetching web pages; I didn't have any specific timeout in mind, and was happy for the library to take care of it. Several million successful http downloads later, my server application thread froze waiting forever when talking to a recalcitrant web-server. I imagine others have fallen for the same trap. While an ideal solution would be for httplib and http.client to use a more generally acceptable default, I can see it might be far too late to make such a change without breaking existing applications. Failing that, I would recommend that the documentation for httplib, urllib, urllib2, http.client and urllib.request (+ any other similar libraries sitting on socket? FTP, SMTP?) be changed to highlight that the default global timeout, sans deliberate override, is to wait a surprisingly long time. ---------- assignee: docs@python components: Documentation, Library (Lib) messages: 104763 nosy: docs@python, oddthinking priority: normal severity: normal status: open title: Unexpected default timeout in http-client-related libraries type: behavior versions: Python 2.6, Python 2.7, Python 3.1 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue8595> _______________________________________

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docs March 2018