Mailman 3 May 2018 - docs

[issue4934] tp_del and tp_version_tag undocumented
by Antoine Pitrou May 12, 2018

May 12, 2018

Antoine Pitrou <pitrou(a)free.fr> added the comment: The reason tp_del has remained undocumented is that it's now obsolete. You should use tp_finalize instead: https://docs.python.org/3/c-api/typeobj.html#c.PyTypeObject.tp_finalize tp_finalize is roughly the C equivalent of __del__ (tp_del was something else, despite the name). ---------- versions: +Python 3.7, Python 3.8 _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue4934> _______________________________________

1 0

[issue4934] tp_del and tp_version_tag undocumented
by book book May 12, 2018

May 12, 2018

book book <book78987book(a)gmail.com> added the comment: tp_del still undocumented. In my opinion, tp_del corresponds to the __del__() method of classes, because there are no other variable correspondes to it, but methods using for creating(tp_new) and initializing(tp_init) an object are not. Although __del__ method have some issue according to the offical document, but it is exist, so there must have a pointer to the function corresponding to it. ---------- nosy: +book book versions: +Python 3.6 -Python 2.6, Python 2.7, Python 3.2, Python 3.3, Python 3.4 _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue4934> _______________________________________

1 0

itertools.product - missing documentation of usage of *
by Madsen, Bjorn May 11, 2018

May 11, 2018

Itertools.product has a "magic" function that isn't documented: The usage of * as precedent to a list of lists of variable length. Example: >>> from itertools import product >>> list(product(*[[-1,1], [-2,-2.5,2], [-3,3]])) [(-1, -2, -3), (-1, -2, 3), (-1, -2.5, -3), (-1, -2.5, 3), (-1, 2, -3), (-1, 2, 3), (1, -2, -3), (1, -2, 3), (1, -2.5, -3), (1, -2.5, 3), (1, 2, -3), (1, 2, 3)] The function works perfectly. The documentation of the usage is missing. Please add it. Kind regards Bjorn Madsen, Ph.D. Head of System Design Tools [Beschreibung: Beschreibung: Beschreibung: Dematic Logo] We Optimise Your Supply Chain Dematic Limited Banbury Business Park Trinity Way Adderbury Banbury OX17 3SN Phone: +44 (0) 7590 306 987 bjorn.madsen(a)dematic.com<mailto:bjorn.madsen@dematic.com> www.dematic.com<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense…>

1 0

[issue33449] Documentation for email.charset confusing about the location of constants
by Francois Labelle May 10, 2018

May 10, 2018

New submission from Francois Labelle <quantum.omega(a)gmail.com>: When mentioning the constants contained in the module email.charset, the documentation prefixes them with "Charset", for example: Charset.QP, Charset.BASE64, Charset.SHORTEST. This suggests that the constants can be found on the class "Charset" (uppercase first letter) in the module, while they are in fact contained in the the "charset" (lowercase first letter) module itself. This is probably a left-over from when the module was called email.Charset (in 2.2 I believe). Under Python 2.7, while the documentation uses the same nomenclature, at least the module is also importable under the name email.Charset so it makes more sense. ---------- assignee: docs@python components: Documentation messages: 316327 nosy: Francois Labelle, docs@python priority: normal severity: normal status: open title: Documentation for email.charset confusing about the location of constants type: enhancement versions: Python 2.7, Python 3.4, Python 3.5, Python 3.6, Python 3.7, Python 3.8 _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue33449> _______________________________________

2 3

[issue33448] Output_Typo_Error
by Mark Dickinson May 10, 2018

May 10, 2018

Mark Dickinson <dickinsm(a)gmail.com> added the comment: Marking as pending; we can't take this forward without more input from the OP. As far as I can tell, the documentation is perfectly correct here: I suspect that there was a misunderstanding somewhere along the line. ---------- assignee: -> docs@python components: +Documentation nosy: +docs@python resolution: -> not a bug status: open -> pending type: resource usage -> _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue33448> _______________________________________

1 0

[issue26701] Documentation for int constructor mentions __int__ but not __trunc__
by Robert Smallshire May 10, 2018

May 10, 2018

New submission from Robert Smallshire: The documentation for the int(x) constructor explains that if possible, it delegates to x.__int__(). The documentation does not explain that there is a fallback to x.__trunc__() if x.__int__() is not available. The only mention of __trunc__ in the Python documentation is in the entry for math.trunc; the documentation for the numbers module does not describe the underlying special methods. Given that all Real numbers are required to implement __trunc__ but only Integral subclasses are required to implement __int__ this could be important to implementers of other Real types, although in practice I imagine that most Real types will implement __int__ as float does. ---------- assignee: docs@python components: Documentation messages: 262941 nosy: Robert Smallshire2, docs@python priority: normal severity: normal status: open title: Documentation for int constructor mentions __int__ but not __trunc__ type: enhancement versions: Python 3.5 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue26701> _______________________________________

6 22

[issue32288] Inconsistent behavior with slice assignment?
by Massimiliano Culpo May 10, 2018

May 10, 2018

New submission from Massimiliano Culpo <massimiliano.culpo(a)googlemail.com>: I am not really sure if what I am reporting is to be considered a bug in the interpreter (slice built-in), a lack in documentation or if it is just me not finding the proper references (in which case feel free to close this and sorry for the noise). Anyhow, while trying to code a class that mimics built-in lists, I noticed a few seemingly inconsistent behaviors in the use of slices to set items. This can be reduced down to this very simple example: ``` Python 3.6.2 (default, Jul 29 2017, 00:00:00) [GCC 4.8.4] on linux # 1. Slice has start and stop, step is defaulted to None >>> a = [1, 2, 3, 4] >>> a[1:3] = [11, 22, 33, 44] >>> a [1, 11, 22, 33, 44, 4] # 2. Same as above setting explicitly step == 1 >>> a = [1, 2, 3, 4] >>> a[1:3:1] = [11, 22, 33, 44] >>> a [1, 11, 22, 33, 44, 4] # 3. Trying to do the same thing with step == -1 # (I naively expected either [1, 44, 33, 22, 11, 4] or 2. to fail like 3.) >>> a = [1, 2, 3, 4] >>> a[3:1:-1] = [11, 22, 33, 44] Traceback (most recent call last): File "<input>", line 1, in <module> ValueError: attempt to assign sequence of size 4 to extended slice of size 2 ``` Now, the first issue: I tried to search what an "extended slice" is exactly, but found nothing in the docs. What is written here https://docs.python.org/3/library/functions.html#slice seems to suggest that an "extended slice" is a slice where `step is not None`, but then I would expect case 2. to behave the same as case 3. So to me it appears as either lack of documentation on the behavior, or a bug in 2. Second issue: in the same page in the docs it's written > slice objects are also generated when extended indexing syntax is used. For example: a[start:stop:step] or a[start:stop, i] I wasn't aware of the second syntax, and tried to use it: ``` >>> a = [1, 2, 3, 4] >>> a[1:3:1] [2, 3] >>> a[1:3, 1] Traceback (most recent call last): File "<input>", line 1, in <module> TypeError: list indices must be integers or slices, not tuple ``` I guess that's not the result one would expect... Third issue: slightly related, but here https://docs.python.org/3/library/stdtypes.html#mutable-sequence-types I see that the documentation of `insert` reads: > inserts x into s at the index given by i (same as s[i:i] = [x]) and from the interpreter: ``` help(list.insert) Help on method_descriptor: insert(...) L.insert(index, object) -- insert object before index ``` Here the fact is that `insert` really behaves like `s[i:i] = [x]`, but in my understanding it doesn't keep the promise to `insert object before index`. ``` # "Out of bounds" on the right >>> a = [1, 2, 3, 4] >>> a.insert(101, 11) >>> a [1, 2, 3, 4, 11] # "Out of bounds" on the left >>> a.insert(-101, 11) >>> a [11, 1, 2, 3, 4] ``` I don't know honestly if docs are not clear here, or if it is just me, but I didn't expect this behavior and thought it was worth reporting. Let me know if you need more information. ---------- assignee: docs@python components: Documentation, Interpreter Core messages: 308120 nosy: Massimiliano Culpo, docs@python priority: normal severity: normal status: open title: Inconsistent behavior with slice assignment? type: behavior versions: Python 2.7, Python 3.4, Python 3.5, Python 3.6 _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue32288> _______________________________________

5 9

issue
by 14JHarvey＠stanwell.org May 9, 2018

May 9, 2018

I am using Python 3.3 the main code is shown in uploaded pic "Capture1". The part in the code that is apparently broken is the Postcode1 variable. As shown in pic "Capture2", after I have converted the entire string to a list (each letter seperated), a c is shown at the front of the list, however, this only occurs sometimes (most of the time as sometimes this does not happen) as shown in "Capture3", when the code loops back round this never occurs. The rest of the pics (4 and onwards) displays the rest of the code, I have also attatched the code. Thanks Disclaimer This email and any attachments are confidential. Unless you are the intended recipient, you may not use, copy or disclose either the message or any information contained within the message. If you are not the intended recipient, you should delete this email and notify the sender immediately. Any views or opinions expressed in this email are those of the sender only and not that of Stanwell School unless otherwise stated. Stanwell School emails and any attachments have not been encrypted; they may therefore be liable to compromise. Please also note that it is your responsibility to scan emails and any attachments for viruses. Stanwell School<http://www.stanwell.org>

1 0

[issue13525] Tutorial: Example of Source Code Encoding triggers error
by Nicolas Goutte May 9, 2018

May 9, 2018

New submission from Nicolas Goutte <nicolas.goutte(a)extragroup.de>: Current Behaviour The tutorial of Python 3.2.x has an example to set an encoding in a source file: http://docs.python.org/py3k/tutorial/interpreter.html#source-code-encoding It explains to set the following line at the start of the source code: # -*- coding: cp-1252 -*- However when done exactly so, Python raises the following exception: SyntaxError: encoding problem: with BOM The problem seems to be that Python knows Windows codepage 1252 as windows-1252 (its IANA charset name, see http://www.iana.org/assignments/charset-reg/windows-1252 ) or alternatively as cp1252 (without dash) but not as cp-1252 (with dash). As this is an example in the tutorial is particularly problematic, as users might not understand how to do it correctly. This is still the case in the tutorial of Python 3.3 alpha: http://docs.python.org/dev/tutorial/interpreter.html#source-code-encoding Expected Behaviour The tutorial should give a correct example, for example with: # -*- coding: windows-1252 -*- Alternatively a totally other example as for Python 2.7 would be nice too: http://docs.python.org/tutorial/interpreter.html#source-code-encoding Notes: I have tested this with following Python implementations: - Python 3.2.1 (openSUSE 12.1) on Linux - Python 3.2.2 on Windows 7 SP1 64 Bits - Python 3.2.2 on MacOS 10.5.8 (Always on the command line; I have not tested in IDLE.) ---------- assignee: docs@python components: Documentation files: cp_1252broken.py messages: 148798 nosy: docs@python, nicolasg priority: normal severity: normal status: open title: Tutorial: Example of Source Code Encoding triggers error versions: Python 3.2 Added file: http://bugs.python.org/file23840/cp_1252broken.py _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue13525> _______________________________________

5 14