Nick Coghlan <ncogh...@gmail.com> added the comment: Note that this isn't about the __class__ reference itself - that would still be a closure cell.
This issue is about the fact that since Python 3.6, type.__new__ has handled calling __set_name__ on all the descriptors, so __build_class__ needs a way to pass the cell over to type.__new__. Currently, the channel for that is the class body execution namespace itself, which created a new requirement for metaclasses to ensure that the "__classcell__" entry actually makes it all the way to "type.__new__". Django at least had to make changes to account for that, and it's mildly disappointing to be imposing that requirement on library and framework authors solely because of a technical limitation in CPython. Even without context chaining, it seems to me that nesting of class definitions could be handled by making the context variable a list of cell objects and having type.__new__ look at the final entry rather than the whole thing. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue33179> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
