Most of the times, I am ending up using isinstance(A, list) or type(A) == list if I can. Therefore I feel like it’s not consistent. And isinstance itself has 10 characters in its name already. Would love to follow == like syntax which we allow to compare types.
I think I have to check how __eq__ is implemented for object before deciding if it’s really inconsistent or not. If the __eq__ is checking over object.__base__ or something similar, then my proposition makes sense. I am not in favor of adding an unnecessary operator writing for base class if it’s not the case. Excuse me if I am talking without really grasping the idea of using == for type comparison. I will do more research. > On 14. Jun 2019, at 21:05, Andrew Svetlov <andrew.svet...@gmail.com> wrote: > > Bad idea. > issubclass() works well. > Adding operator support should be considered very carefully. > I prefer a good portion of conservatism for such changes. > How often the proposed change is needed? > It adds a new complexity (documenting, teaching etc) without real > benefits for daily jobs. > >> On Fri, Jun 14, 2019 at 9:42 PM Joao S. O. Bueno <jsbu...@python.org.br> >> wrote: >> >> And yet: >> >> This is trivial to implement in a custom metaclass - >> and maybe it would make default type too "noisy". >> >> I am -1 on this going into normal classes, >> and +0 for having a colaborative >> metaclass with __lt__, __eq__ and such implementing >> these on the stdlib. Maybe living in "types". >> >> >> >> >> >>> On Fri, 14 Jun 2019 at 14:53, Brett Cannon <br...@python.org> wrote: >>> >>> I think the logic breaks down with multiple inheritance. If you make C(A, >>> B), then you can say C > A and C > B, but then you can't say A > B or A < B >>> which breaks sorting. >>> >>> If you want to know if a B inherits from Base, then I think `Base in >>> B.mro()` will cover that just as succinctly. And if you need to know >>> position you can compare indexes into the MRO. >>> >>>> On Fri, Jun 14, 2019 at 1:06 AM eminbugrasaral--- via Python-ideas >>>> <python-ideas@python.org> wrote: >>>> >>>> Let's assume you have this model: >>>> >>>> ``` >>>> class Base: >>>> pass >>>> >>>> class A(Base): >>>> pass >>>> >>>> class B(Base): >>>> pass >>>> >>>> class C(A): >>>> pass >>>> ``` >>>> >>>> While we can do `A == B`, or `B == C` or `B == B`, I would expect to be >>>> able to compare like this as well: `A >= B (if B is subclass or itself of >>>> A)`, or `B <= C (if B is a subclass or itself of C)` >>>> >>>> Because, since == means equality check. With the same logic, a class wraps >>>> another class is actually greater than this class from its type. >>>> _______________________________________________ >>>> Python-ideas mailing list -- python-ideas@python.org >>>> To unsubscribe send an email to python-ideas-le...@python.org >>>> https://mail.python.org/mailman3/lists/python-ideas.python.org/ >>>> Message archived at >>>> https://mail.python.org/archives/list/python-ideas@python.org/message/6W7HCI4UIEAUD6AVLFSJF5Q2X55LWYZA/ >>>> Code of Conduct: http://python.org/psf/codeofconduct/ >>> >>> _______________________________________________ >>> Python-ideas mailing list -- python-ideas@python.org >>> To unsubscribe send an email to python-ideas-le...@python.org >>> https://mail.python.org/mailman3/lists/python-ideas.python.org/ >>> Message archived at >>> https://mail.python.org/archives/list/python-ideas@python.org/message/IFW2UQNCCNYFZH3TFKD26WH7SKCP4YKT/ >>> Code of Conduct: http://python.org/psf/codeofconduct/ >> >> _______________________________________________ >> Python-ideas mailing list -- python-ideas@python.org >> To unsubscribe send an email to python-ideas-le...@python.org >> https://mail.python.org/mailman3/lists/python-ideas.python.org/ >> Message archived at >> https://mail.python.org/archives/list/python-ideas@python.org/message/UYNPZXZQQQQHNH7CW5M64ZFT2XKL2HPE/ >> Code of Conduct: http://python.org/psf/codeofconduct/ > > > > -- > Thanks, > Andrew Svetlov _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/V5FGNQG2RNDMJ26ZJAXVSKKIJEWDIFX4/ Code of Conduct: http://python.org/psf/codeofconduct/
