[issue16837] Number ABC can be instantiated

Change by Raymond Hettinger : -- resolution: -> wont fix stage: patch review -> resolved status: open -> closed ___ Python tracker ___

[issue16837] Number ABC can be instantiated

Guido van Rossum added the comment: Let's not do this. We've survived this long. -- ___ Python tracker ___ ___ Python-bugs-list

[issue16837] Number ABC can be instantiated

Raymond Hettinger added the comment: I looked into this a bit more and don't see another non-invasive way of blocking instantiation. Marking for Guido to take a look at. He's the expert on ABCs and typing and is the originator of the __hash__ = None approach to turning off hashability.

[issue16837] Number ABC can be instantiated

Raymond Hettinger added the comment: Usually, setting hash to None is the proper way to turn-off hashability. And it's possible that existing code has subclassed Number and provided other methods but not __hash__, so this could potentially break their code. On the other hand, it would be

[issue16837] Number ABC can be instantiated

Sanyam Khurana added the comment: I'm changing the versions to Python 3.8 and 3.9 for this bug. -- versions: +Python 3.8, Python 3.9 -Python 3.4, Python 3.5 ___ Python tracker

[issue16837] Number ABC can be instantiated

Sanyam Khurana added the comment: Hi Alexander, Can you please address the reviews and turn this patch into a GitHub PR, please? -- nosy: +CuriousLearner ___ Python tracker

[issue16837] Number ABC can be instantiated

Berker Peksag added the comment: I left a couple of comments on Rietveld. -- nosy: +berker.peksag ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16837 ___

[issue16837] Number ABC can be instantiated

Changes by Claudiu Popa pcmantic...@gmail.com: -- components: +Library (Lib) versions: +Python 3.5 -Python 3.3 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16837 ___

[issue16837] Number ABC can be instantiated

Claudiu Popa added the comment: I'd say that this should be fixed, it breaks the expectancy imposed by the documentation, so +1 from me. -- nosy: +Claudiu.Popa ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue16837

[issue16837] Number ABC can be instantiated

Alexander Belopolsky added the comment: Attached patch fixes the issue and passes regression tests, so most likely the ability to instantiate Number is not an intentional feature. pass should probably be replaced with a meaningful docstring, but I would like to hear from others on whether the

[issue16837] Number ABC can be instantiated

New submission from Alexander Belopolsky: According to the reference manual, None of the types defined in [numbers] module can be instantiated. However, from numbers import * Number() numbers.Number object at 0x1005e5080 This can probably be fixed by making Number.__hash__ an abstract