Ken Jin <kenjin4...@gmail.com> added the comment:
@Paul, Steve, Tim and Zach, I've removed y'all from nosy as this isn't a Windows issue (but a typing/builtin types one). If you feel that I shouldn't have done that: my apologies and please do tell me. To summarize what OP said: >>> isinstance(bool, (bool, list[bool])) TypeError: isinstance() argument 2 cannot be a parameterized generic >>> issubclass(bool, (bool, list[bool])) True @OP, this seems like a bug. issubclass should raise according to PEP 585. In this case it's short-circuiting so it doesn't check the 2nd arg. Swapping the arguments around gives the expected TypeError. >>> issubclass(bool, (list[bool], bool)) TypeError: issubclass() argument 2 cannot be a parameterized generic At the same time, I'm hesitant to run a check through everything in the types tuple first. That would hurt issubclass performance (I'm not sure by how much). What do you think, Guido and Serhiy? ---------- components: +Library (Lib) -Tests, Windows nosy: +gvanrossum, kj, serhiy.storchaka -paul.moore, steve.dower, tim.golden, zach.ware versions: +Python 3.11, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue44932> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
