Mailman 3 July 2018 - docs

[issue29323] Wrong documentation (Library) for unicode and str comparison
by RK-5wWm9h May 31, 2020

May 31, 2020

New submission from RK-5wWm9h: PROBLEM (IN BRIEF): In the currently published 2.7.13 The Python Standard Library (Library Reference manual) section 5.6 "Sequence Types" (https://docs.python.org/2/library/stdtypes.html#sequence-types-str-unicode-…): "to compare equal, ... the two sequences must be of the same type" This an *incorrect (and misleading) statement*, for the unicode and str case. PROPOSED FIX: Current full paragraph: "Sequence types also support comparisons. In particular, tuples and lists are compared lexicographically by comparing corresponding elements. This means that to compare equal, every element must compare equal and the two sequences must be of the same type and have the same length. (For full details see Comparisons in the language reference.)" Proposed replacement text: "Sequence types also support comparisons. In particular, tuples and lists are compared lexicographically by comparing corresponding elements. This means that to compare equal, every element must compare equal and the two sequences must be of the same type and have the same length. (Unicode and str are treated as the same type here; for full details see Comparisons in the language reference.)" DETAILS, JUSTIFICATION, CORRECTNESS, ETC: The current incorrect text is really misleading. The behaviour that a str and a unicode object -- despite being objects of different types -- may compare equal, is explicitly stated in the 2.7.13 The Python Language Reference manual, section 5.9 "Comparisons" (https://docs.python.org/2/reference/expressions.html#comparisons): "* Strings are compared lexicographically using the numeric equivalents (the result of the built-in function ord()) of their characters. Unicode and 8-bit strings are fully interoperable in this behavior. [4]" (Aside: Incidentally an earlier paragraph in the Language Ref fails to cover the unicode and str case; see separately filed bug Issue 29321.) ---------- assignee: docs@python components: Documentation messages: 285792 nosy: RK-5wWm9h, docs@python priority: normal severity: normal status: open title: Wrong documentation (Library) for unicode and str comparison type: behavior versions: Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue29323> _______________________________________

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[issue26433] urllib.urlencode() does not explain how to handle unicode
by Thomas Güttler May 31, 2020

May 31, 2020

New submission from Thomas Güttler: The current docs for Python2, don't explain how to handle unicode: https://docs.python.org/2/library/urllib.html#urllib.urlencode It seems to be a common problem. See http://stackoverflow.com/questions/6480723/urllib-urlencode-doesnt-like-uni… It would be nice to document the most pythonic way to handle unicode in urllib.urlencode() ---------- assignee: docs@python components: Documentation messages: 260845 nosy: Thomas Güttler, docs@python priority: normal severity: normal status: open title: urllib.urlencode() does not explain how to handle unicode versions: Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue26433> _______________________________________

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[issue24256] threading.Timer is not a class
by John Runyon May 31, 2020

May 31, 2020

New submission from John Runyon: the documentation (https://docs.python.org/2/library/threading.html#threading.Timer) lists "threading.Timer" as a class. It is not, which means that (for example) you can not use it in isinstance(). "threading._Timer" is a class. "threading.Timer(...).__class__" is a class. "threading.Timer" is a function. >>> import threading >>> threading.Timer <function Timer at 0x7f99cae23848> ---------- assignee: docs@python components: Documentation messages: 243735 nosy: docs@python, jrunyon priority: normal severity: normal status: open title: threading.Timer is not a class versions: Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue24256> _______________________________________

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[issue25511] multiprocessing pool blocks SIGTERM from being handled
by David Jones May 31, 2020

May 31, 2020

New submission from David Jones: This is probably related to #21913, but more specifically concerns the documentation. I have a sub process of a larger program that handles a SIGTERM sent by the main process for a clean shutdown. However, if I launch a parallel task in the sub process, via multiprocessing.Pool.imap_unordered, all signals are blocked until pool finishes running the task. If this isn't going to be fixed, then it ought to at least be clearly documented. It took a very long time to diagnose this problem. It requires a programmer to understand the underlying implementation of a high-level construct, thus defeating the purpose of using a high level construct. Also, is there a way to work around this? ---------- assignee: docs@python components: Documentation messages: 253678 nosy: djones, docs@python priority: normal severity: normal status: open title: multiprocessing pool blocks SIGTERM from being handled type: behavior versions: Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue25511> _______________________________________

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[issue22052] Comparison operators called in reverse order for subclasses with no override.
by Mark Dickinson May 31, 2020

May 31, 2020

New submission from Mark Dickinson: As reported in a StackOverflow question [1]: the order in which the special comparison methods are called seems to be contradictory to the docs [2]. In the following snippet, __eq__ is called with reversed operands first: >>> class A: ... def __eq__(self, other): ... print(type(self), type(other)) ... return True ... >>> class B(A): ... pass ... >>> A() == B() <class '__main__.B'> <class '__main__.A'> True However, the docs note that: """If the right operand’s type is a subclass of the left operand’s type and that subclass provides the reflected method for the operation, this method will be called before the left operand’s non-reflected method. This behavior allows subclasses to override their ancestors’ operations.""" ... which suggests that this reversal should only happen when the subclass B *overrides* A's definition of __eq__ (and indeed that's the usual behaviour for arithmetic operations like __add__). Looking more closely, that statement in the docs is in the 'numeric-types' section, so it's not clear that its rules should apply to the comparison operators. But either way, some doc clarification could be useful. [1] http://stackoverflow.com/q/24919375/270986 [2] https://docs.python.org/3.5/reference/datamodel.html#emulating-numeric-types ---------- assignee: docs@python components: Documentation messages: 223778 nosy: docs@python, mark.dickinson priority: normal severity: normal status: open title: Comparison operators called in reverse order for subclasses with no override. versions: Python 2.7, Python 3.4, Python 3.5 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue22052> _______________________________________

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[issue23514] multiprocessing documentation - little more examples for parallel computing
by Cezary Wagner May 31, 2020

May 31, 2020

New submission from Cezary Wagner: I am little confused with multiprocessing documentation since it does not contain enough examples. Parallel computing is not simple by design so documentation can be little improved to make it simpler. No pattern to use pool with classes. No pattern to exchange objects between processes. Understanding usage of Queue and SimpleQueue or JoinableQueue is not very clear. Current documentation in majority is good reference with very rare examples / patterns. ---------- assignee: docs@python components: Documentation messages: 236519 nosy: Cezary.Wagner, docs@python priority: normal severity: normal status: open title: multiprocessing documentation - little more examples for parallel computing _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue23514> _______________________________________

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[issue20296] PyArg_ParseTuple 2.X docs mention int for "t#", but "Py_ssize_t" for "w#", etc.
by Rob Browning May 31, 2020

May 31, 2020

New submission from Rob Browning: Here (http://docs.python.org/2/c-api/arg.html), the documentation for "t#" says: t# (read-only character buffer) [char *, int]... while the documentation for "w#" says: w# (read-write character buffer) [char *, Py_ssize_t]... However, from getargs.c, it looks like they're handled the same with respect to the size type. At a minimum, it seems like it might make sense to change these docs to match, and if "w#" and "t#" are actually handled similarly to "s#", it would be even better to just change their docs to match (or refer to) "s#"'s which are more detailed, i.e. they mention the PY_SSIZE_T_CLEAN issues, etc. Thanks ---------- assignee: docs@python components: Documentation messages: 208410 nosy: docs@python, rlb priority: normal severity: normal status: open title: PyArg_ParseTuple 2.X docs mention int for "t#", but "Py_ssize_t" for "w#", etc. versions: Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue20296> _______________________________________

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[issue21547] '!s' formatting documentation bug
by Joshua Landau May 31, 2020

May 31, 2020

New submission from Joshua Landau: In the docs for 2.x about the formatting syntax: https://docs.python.org/2/library/string.html#format-string-syntax it says "Two conversion flags are currently supported: '!s' which calls str() on the value, and '!r' which calls repr()." but for unicode formatters, '!s' calls unicode() instead. See http://stackoverflow.com/questions/23773816/why-python-str-format-doesnt-ca… for the question that found this. ---------- assignee: docs@python components: Documentation messages: 218863 nosy: Joshua.Landau, docs@python priority: normal severity: normal status: open title: '!s' formatting documentation bug versions: Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue21547> _______________________________________

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[issue9196] Improve docs for string interpolation "%s" re Unicode strings
by Craig McQueen May 31, 2020

May 31, 2020

New submission from Craig McQueen <python(a)craig.mcqueen.id.au>: I have just been trying to figure out how string interpolation works for "%s", when Unicode strings are involved. It seems it's a bit complicated, but the Python documentation doesn't really describe it. It just says %s "converts any Python object using str()". Here is what I have found (I think), and it could be worth improving the documentation of this somehow. Example 1: "%s" % test_object >From what I can tell, in this case: 1. test_object.__str__() is called. 2. If test_object.__str__() returns a string object, then that is substituted. 3. If test_object.__str__() returns a Unicode object (for some reason), then test_object.__unicode__() is called, then _that_ is substituted instead. The output string is turned into Unicode. This behaviour is surprising. [Note that the call to test_object.__str__() is not the same as str(test_object), because the former can return a Unicode object without causing an error, while the latter, if it gets a Unicode object, will then try to encode('ascii') to a string, possibly generating a UnicodeEncodeError exception.] Example 2: u"%s" % test_object In this case: 1. test_object.__unicode__() is called, if it exists, and the result is substituted. The output string is Unicode. 2. If test_object.__unicode__() doesn't exist, then test_object.__str__() is called instead, converted to Unicode, and substituted. The output string is Unicode. Example 3: "%s %s" % (u'unicode', test_object) In this case: 1. The first substitution causes the output string to be Unicode. 2. It seems that (1) causes the second substitution to follow the same rules as Example 2. This is a little surprising. ---------- assignee: docs@python components: Documentation messages: 109516 nosy: cmcqueen1975, docs@python priority: normal severity: normal status: open title: Improve docs for string interpolation "%s" re Unicode strings versions: Python 2.7 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue9196> _______________________________________

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[issue20686] Confusing statement
by Daniel U. Thibault May 31, 2020

May 31, 2020

New submission from Daniel U. Thibault: Near the end of 3.1.3 http://docs.python.org/2/tutorial/introduction.html#unicode-strings you can read: "When a Unicode string is printed, written to a file, or converted with str(), conversion takes place using this default encoding." This can be interpreted as stating that stating that printing a Unicode string (using the print function or the shell's default print behaviour) results in ASCII printout. It can likewise be interpreted as stating that any write of a Unicode string to a file converts the string to ASCII. Experimentation shows this is not true. Perhaps you meant something like this: "When a Unicode string is converted with str() in order to be printed or written to a file, conversion takes place using this default encoding." Grammatical comments: In the statement "When a Unicode string is printed, written to a file, or converted with str(), conversion takes place using this default encoding.", the ", or" puts the three elements of the enumeration on the same level (respectively "printed", "written to a file", and "converted with str()"). The confusion seems to arise because "with str()" was meant to apply to the list as a whole, not just its last element. ---------- assignee: docs@python components: Documentation messages: 211627 nosy: Daniel.U..Thibault, docs@python priority: normal severity: normal status: open title: Confusing statement type: enhancement _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue20686> _______________________________________

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