Mailman 3 March 2020 - docs

[issue32377] Difference in ressurrection behavior with __del__ in py2 vs. py3
by Eric Cousineau April 9, 2020

April 9, 2020

New submission from Eric Cousineau <eric.cousineau(a)tri.global>: Due to how `PyObject_CallFinalizer` is written in python3, `__del__` will only *ever* be called once. In my use case, I am experimenting with a feature in `pybind11` to prevent slicing with Python class instances that inherit from pybind11-C++ base classes, which involves detecting when an instance loses all reference in Python (`Py_REFCNT(...) == 0`) but still has reference in C++ (`shared_ptr::count() > 0`), and reviving the Python portion when this situation happens. In python2, I could do this without a hitch, as a resurrected object could have its `__del__` method called multiple times (through `tp_dealloc` I believe?). But in python3, the object is marked with `_PyGC_SET_FINALIZED(...)`, thus preventing `__del__` from being called again. It'd be nice to either (a) somehow allow `__del__` to be called naturally without too much fuss or, at the least, (b) have this reflected in the documentation: https://docs.python.org/3/reference/datamodel.html#object.__del__ See attached `revive_test`. Example execution: ``` $ python2 ./revive_test.py Revive Destroy [ Done ] $ python3 ./revive_test.py Revive [ Done ] ``` ---------- assignee: docs@python components: Documentation files: revive_test.py messages: 308660 nosy: Eric Cousineau, docs@python priority: normal severity: normal status: open title: Difference in ressurrection behavior with __del__ in py2 vs. py3 type: behavior versions: Python 3.4, Python 3.5, Python 3.6 Added file: https://bugs.python.org/file47339/revive_test.py _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue32377> _______________________________________

3 11

[issue40127] Documentation of SSL library
by Christophe Nanteuil April 4, 2020

April 4, 2020

New submission from Christophe Nanteuil <christophe.nanteuil(a)gmail.com>: For the ssl.create_default_context() function, it states that, "if cafile, capath and cadata are None, the function *can* choose to trust the system's default CA certificates instead". This statement is not clear as, if the values are None, there is no choice and the only elements available are system's default CA. AFAIK, if the values are not None, it will not fall back to system's default CA even if the given CA does not match. I propose to modify the end of the sentence with "the function trusts the system's default CA certificates instead". ---------- assignee: docs@python components: Documentation messages: 365398 nosy: Christophe Nanteuil, docs@python priority: normal severity: normal status: open title: Documentation of SSL library 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/issue40127> _______________________________________

3 6

[issue40131] Zipapp example has parameters in the wrong order
by Leron Gray April 3, 2020

April 3, 2020

New submission from Leron Gray <daddycocoaman(a)gmail.com>: The second example listed here for zipapp has the parameters in the wrong order. https://docs.python.org/3/library/zipapp.html?highlight=zipapp#examples It should be create_archive("myapp", "myapp.pyz") since the parameters are (source, target). The documentation for the function itself is correct though. ---------- assignee: docs@python components: Documentation messages: 365436 nosy: Leron Gray, docs@python priority: normal severity: normal status: open title: Zipapp example has parameters in the wrong order type: enhancement versions: 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/issue40131> _______________________________________

4 7

Bug in documentation of mailbox.Maildir
by Stefan Witzel April 3, 2020

April 3, 2020

Hi, I think there is a bug in the documentation of "class mailbox.Maildir". If the dirname path exists it will be accepted as a Maildir directory. If the dirname path not exists and create is True a new Maildir directory will be created, otherwise the interpreter raises a mailbox.NoSuchMailboxError exception. Stefan -- Stefan Witzel st.witzel(a)web.de

2 1

Official Documentation Error on Nan
by arnuld April 3, 2020

April 3, 2020

Hi There, You are receiving email because it was written at the bottom of this page: https://docs.python.org/3/reference/expressions.html I think I found a documentation error (bug?) . In section "6.10.1. Value comparisons", it is written: "The not-a-number values float('NaN') and decimal.Decimal('NaN') are special. Any ordered comparison of a number to a not-a-number value is false. A counter-intuitive implication is that not-a-number values are not equal to themselves. For example, if x = float('NaN'), 3 < x, x < 3, x == x, x != x are all false. This behavior is compliant with IEEE 754." Last comparison "x != x" does not return False, it returns True. In [86]: x == y Out[86]: False In [87]: x != y Out[87]: True I checked it on Wikipedia too: https://en.wikipedia.org/wiki/NaN#Comparison_with_NaN Please correct me if I am wrong. I don't want to waste anyone's time. -- Regards, ARNULD https://medium.com/@ArnuldOnData https://www.linkedin.com/in/arnuld-on-data/

2 1

Possible issue in string formatting
by Shlomo Gottlieb April 3, 2020

April 3, 2020

Hi, I noticed that when using string format to print hexadecimal numbers like the following: *>>> '{:#X}'.format(1234)* *'0X4D2'* I get an uppercase 'X' which in my opinion should remain lowercase 'x' (like: *'0x4D2'*) If you think it should be like it is today all uppercase then I'd suggest to add it in the docs. Today the docs state (here <https://docs.python.org/3/library/string.html#string-formatting>): 'X' Hex format. Outputs the number in base 16, using upper-case letters for the digits above 9. I think we should add a some comment like: *Note: In case # is specified, the prefix '0x' will be uppercased as well.* Regards, Shlomo Gottlieb

2 1

[issue15140] PEP 384 inconsistent with implementation
by Antoine Pitrou April 1, 2020

April 1, 2020

New submission from Antoine Pitrou <pitrou(a)free.fr>: In PEP 384, the PyType_Spec struct has a "const char *doc" that is not present in the implementation (Include/object.h). ---------- assignee: docs@python components: Documentation messages: 163449 nosy: docs@python, loewis, pitrou priority: normal severity: normal stage: needs patch status: open title: PEP 384 inconsistent with implementation type: behavior _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue15140> _______________________________________

4 3

Typo in https://docs.python.org/3/howto/regex.html
by Hoàng Tuấn Việt March 31, 2020

March 31, 2020

Hi, I found a typo. Please help to fix this. Current: Now imagine matching this RE against the string 'abcbd'. Expected: Now imagine matching this RE against the string 'abcb'. (remove 'd' at the end of the sentence) Thanks, Viet Hoang

2 2

Typo in datetime.timezone docs
by Peter Dimitrov March 31, 2020

March 31, 2020

Hello, I believe I have found a typo in these docs - https://docs.python.org/3/library/datetime.html#datetime.timezone Where it says: > The *offset* argument must be specified as a timedelta > <https://docs.python.org/3/library/datetime.html#datetime.timedelta> object > representing the difference between the local time and UTC. It must be > strictly between -timedelta(hours=24) and timedelta(hours=24), otherwise > ValueError <https://docs.python.org/3/library/exceptions.html#ValueError> is > raised. I think it should be: timedelta(hours=24) and timedelta(hours=*-24*) Best Regards, Peter Dimitroff

2 1

[issue40122] The implementation and documentation of "dis.findlables" don't match
by STINNER Victor March 31, 2020

March 31, 2020

Change by STINNER Victor <vstinner(a)python.org>: ---------- nosy: -vstinner _______________________________________ Python tracker <report(a)bugs.python.org> <https://bugs.python.org/issue40122> _______________________________________

1 0