[issue19431] Document PyFrame_FastToLocals() and PyFrame_FastToLocalsWithError()
João Sebastião de Oliveira Bueno <gwid...@gmail.com> added the comment: This discussion is fresh, so maybe it is worth asking here prior to python-ideas: In Python we can change any global variable, object attribute or mapping-value with function calls. Locals and nonlocals are the only exceptions and from time to time that gets in the way of clever oneliners, and it is just plain asymmetric. What do you say of adding a wrapper to this as an oficial Python function in the stdlib? Maybe inspect.setlocal() that could set f_locals and call this?? That would provide a workaround to the asymmetry that locals currently experiment. It would not impose any extra security risks, since this can be called via ctypes already, and also it is not any more subject to abuse than setattr or globals()[...] = can already be abused. -- nosy: +João.Sebastião.de.Oliveira.Bueno ___ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue19431> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue28672] Explain in the "Data Model" document why arguments to __init__ are ok when __new__ is not defined
New submission from João Sebastião de Oliveira Bueno: There is an specific Python behavior on object instantiation that is "expected" but not explicit, even for avanced users: When a custom class defines `__init__` with extra parameters, but do not overrides `__new__`, it simply works. But if `__new__`is defined it has to match `__init__`s signature. This behavior is not documented anywhere. I could found this issue was discussed in this thread earlier this year, starting with this e-mail: https://mail.python.org/pipermail/python-list/2016-March/704013.html I propose the following paragraph from a follow up e-mail by "eryksun at gmail.com" to be added to the description of "__new__" in the Data Model documentation page: """ [The implementation] knows whether a type overrides the __new__ or __init__ methods. You're expected to consume additional arguments in this case. However, excess arguments are ignored in object.__new__ if a type overrides __init__ without overriding __new__ (i.e. your second example). Excess arguments are also ignored in object.__init__ if a type overrides __new__ without overriding __init__. """ (Source: https://mail.python.org/pipermail/python-list/2016-March/704024.html) -- assignee: docs@python components: Documentation messages: 280633 nosy: João.Sebastião.de.Oliveira.Bueno, docs@python priority: normal severity: normal status: open title: Explain in the "Data Model" document why arguments to __init__ are ok when __new__ is not defined type: enhancement versions: Python 3.6 ___ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue28672> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue11842] slice.indices with negative step and default stop
João Sebastião de Oliveira Bueno gwid...@gmail.com added the comment: I don't see this as a bug. The indices returned in both cases are exactly what you need to feed to range, in order to get the correct indices for the provided slice parameters. Perceive that if for s = slice(None, None, -2) It would return anything different from (9, -1, -2) It would be impossible to properly generate the desired indices. (With a 0 instead of -1, we would be missing the last index). When you pass these numbers with the [ ] notation for being used as indices, the negative index is interpreted as len(sequence) - index. In the case of -1 in your example it is the same as 9 not the same as one before zero. I recommend closing this as not a bug. -- nosy: +João.Sebastião.de.Oliveira.Bueno ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11842 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
