Mailman 3 June 2019 - docs

[issue21492] email.header.decode_header sometimes returns bytes, sometimes str
by Terry J. Reedy 07 Jun '19

07 Jun '19

Change by Terry J. Reedy <tjreedy(a)udel.edu>: ---------- versions: +Python 3.7, Python 3.8, Python 3.9 -Python 3.3 _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue21492> _______________________________________

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[issue37134] Use PEP570 syntax in the documentation
by Pablo Galindo Salgado 06 Jun '19

06 Jun '19

New submission from Pablo Galindo Salgado <pablogsal(a)gmail.com>: In the documentation, there are a lot of mismatches regarding function and method signatures that use positional-only arguments with respect to the docstrings (that properly use PEP570 syntax for documenting positional-only parameters). Not that the official syntax for positional-only parameters is accepted (the "/"), the documentation needs to be updated to reflect positional-only parameters in the functions and methods that use them as covered in the PEP document. ---------- assignee: docs@python components: Documentation messages: 344295 nosy: docs@python, pablogsal priority: normal severity: normal status: open title: Use PEP570 syntax in the documentation versions: Python 3.8 _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue37134> _______________________________________

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[issue37145] collections.abc.MappingView mixins rely on undocumented _mapping
by Geoffrey Sneddon 04 Jun '19

04 Jun '19

New submission from Geoffrey Sneddon <geoffers+pythonbugs(a)gmail.com>: The mixin methods on MappingView and its subclasses all rely on the undocumented MappingView._mapping (set in the undocumented MappingView.__init__). This should probably be documented at least insofar as Set._from_iterable is. ---------- assignee: docs@python components: Documentation messages: 344447 nosy: docs@python, gsnedders priority: normal severity: normal status: open title: collections.abc.MappingView mixins rely on undocumented _mapping type: behavior versions: Python 2.7, Python 3.5, Python 3.6, Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue37145> _______________________________________

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[issue30699] Misleading class names in datetime.tzinfo usage examples
by Robert Tasarz 04 Jun '19

04 Jun '19

New submission from Robert Tasarz: https://docs.python.org/3/library/datetime.html#datetime-objects gives in an example two classes named GMT1 and GMT2 subclassing tzinfo, defined with dst(…) methods returning one hour timedelta for summer periods. This is in conflict with naming, as GMT timezone is not defined with any daylight saving time, so any timezone offsetted from it shouldn't be as well. I would suggest renaming them to something like BrusselsTZ and HelsinkiTZ (with a comment that this is simplified implementation, that doesn't account for exact hour when dst switch is made, and maybe mentioning pytz) and tzname(…) to return ('CET', 'CEST')[bool(self.dst(dt))] and ('EET', 'EEST')[bool(self.dst(dt))] accordingly. Also https://docs.python.org/3/library/datetime.html#time-objects has an example with GMT1 class, though this time dst(…) unconditionally returns offset 0 properly, tzname(…) gives 'Europe/Prague' – region that uses dst. IMHO returning any of: "CET", "GMT+1", "Africa/Tunis" would be better here. ---------- assignee: docs@python components: Documentation messages: 296296 nosy: Robert.Tasarz, docs@python priority: normal severity: normal status: open title: Misleading class names in datetime.tzinfo usage examples type: enhancement versions: Python 2.7, Python 3.6 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue30699> _______________________________________

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Embedding Python in Another Application tutorial problem
by Ibarra, Jesse 04 Jun '19

04 Jun '19

Hi, I am working on CentOS7 I am trying the 1.1 Very High Level Embedding I am using Python 3.7.3 (default, Mar 27 2019, 22:11:17) [GCC 7.3.0] :: Anaconda, Inc. on linux I created a file by pasting the tutorial code into original.c #define PY_SSIZE_T_CLEAN #include <Python.h> int main(int argc, char *argv[]) { wchar_t *program = Py_DecodeLocale(argv[0], NULL); if (program == NULL) { fprintf(stderr, "Fatal error: cannot decode argv[0]\n"); exit(1); } Py_SetProgramName(program); /* optional but recommended */ Py_Initialize(); PyRun_SimpleString("from time import time,ctime\n" "print('Today is', ctime(time()))\n"); if (Py_FinalizeEx() < 0) { exit(120); } PyMem_RawFree(program); return 0; } After executing: gcc -o original original.c original.c:2:20: fatal error: Python.h: No such file or directory #include <Python.h> ^ compilation terminated. What am I doing wrong? Is the tutorial complete? Thanks, Jesse

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Fw: Download issues for Python
by tom milikic 04 Jun '19

04 Jun '19

Hi my name is Tom and I come from Brisbane in Australia. I cannot seem to download Python on my computer as I really need it to help with my Quantitative Finance studies. It seems to say that some program is missing from my computer? What do I do? I am running Windows and a Toshiba computer. I have looked in the help section and I still cant seem to fix or find the issue with why it is not downloading onto my computer? It states that this is missing from my computer -: api-ms-win-crt-runtime-l1-1-0.dl Also Python 3.7.2 and Python 3.7.3 appear in my download folders but when I click them nothing happens? If you can help would be much appreciated Thanks Tom [https://ipmcdn.avast.com/images/icons/icon-envelope-tick-round-orange-anima…]<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> Virus-free. www.avast.com<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…>

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[issue21492] email.header.decode_header sometimes returns bytes, sometimes str
by Ezio Melotti 04 Jun '19

04 Jun '19

Ezio Melotti <ezio.melotti(a)gmail.com> added the comment: If we can't fix the behavior, it should at least be documented. Currently the docs says "This function returns a list of (decoded_string, charset) pairs containing each of the decoded parts of the header.". One could assume that this means that a Unicode string is returned, but and as far as I can tell, "decoded_string" means decoded from the format used by the header, not from bytes -- in fact the example below shows a byte string. #24797 suggest an alternative solution, but there is no indications about it in the docs except an easy-to-miss note about the new API at the top. Coincidentally as I was reporting this issue I also found the recently opened #37139. There are also a few other reports: #24797, #37139, #32975, #6302, #4661. If this method is not actually deprecated, I would document the current behavior (i.e. sometimes it returns bytes, sometimes unicode -- bonus points if there's a simple rule to predict which one), explain that it exists for legacy/backward-compatibility reasons, and point to the alternatives. FWIW here are 3 more samples that show the inconsistency. >>> from email.header import decode_header >>> # str + None >>> h = '\x80SOKCrGxsbw===== <hello(a)example.com>'; decode_header(h) [('\x80SOKCrGxsbw===== <hello(a)example.com>', None)] >>> # bytes + '', bytes + None >>> h = '=??b?SOKCrGxsbw=====?= <hello(a)example.com>'; decode_header(h) [(b'H\xe2\x82\xacllo', ''), (b' <hello(a)example.com>', None)] >>> # bytes + 'utf8', bytes + None >>> h = '=?utf8?b?SOKCrGxsbw==?= <hello(a)example.com>'; decode_header(h) [(b'H\xe2\x82\xacllo', 'utf8'), (b' <hello(a)example.com>', None)] ---------- assignee: -> docs@python components: +Documentation nosy: +docs@python, ezio.melotti, louis.abraham(a)yahoo.fr resolution: duplicate -> stage: resolved -> needs patch status: closed -> open type: behavior -> enhancement _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue21492> _______________________________________

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[issue26468] shutil.copy2 raises OSError if filesystem doesn't support chmod
by Windson Yang 03 Jun '19

03 Jun '19

Change by Windson Yang <wiwindson(a)outlook.com>: ---------- keywords: +patch pull_requests: +13651 stage: -> patch review pull_request: https://github.com/python/cpython/pull/13765 _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue26468> _______________________________________

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[issue19184] dis module has incorrect docs for RAISE_VARARGS
by Ned Batchelder 02 Jun '19

02 Jun '19

New submission from Ned Batchelder: The order of values on the stack is backwards for RAISE_VARARGS. The docs say: "Raises an exception. argc indicates the number of parameters to the raise statement, ranging from 0 to 3. The handler will find the traceback as TOS2, the parameter as TOS1, and the exception as TOS." But in fact, the order is reverse of that. In the one-parameter case, the exception is TOS, in the two-parameter case, the value is TOS, and in the three-parameter case, the traceback is TOS. Not sure how to write that concisely, thought. :) ---------- assignee: docs@python components: Documentation keywords: easy messages: 199096 nosy: docs@python, nedbat priority: normal severity: normal status: open title: dis module has incorrect docs for RAISE_VARARGS versions: Python 2.7, Python 3.4 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue19184> _______________________________________

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I understand this is not a bug, but ..
by Ola K 02 Jun '19

02 Jun '19

I understand this is not a bug, but problems like this that feels "too simple to ask about" form me is really annoying as a newbie because it opens the lid on the programming culture as a whole I guess and by that I am referring to the overall messy sea of different languages one have to decide where to start navigate, the abundance of litterature connected to the language of choice, the abundance of IDE:s, forums, moduls and packages vs another enviroment, (yet another galaxy). I understands this is because programming is used for all walks of life. But yet after months of studying, navigating, installing, targeting/ choosing platform, I come back to this "the king has no clothes" question: What is the difference between an "editor of choice" and a "python interpreter"? I was following an example wich I now ironically lost among all my millions of open tabs. I know you can´t help me now because I lost the adress to that place and because this is not the proper way of asking questions, but anyway, see this message as a reality check if you feel like it. Bye thank you for everything (keeping up the struggle for my better future). //Ola For instance, use your favorite text editor

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