Guido van Rossum <gu...@python.org> added the comment: I fear that this is one of those cases that will longer in the tracker forever. We probably shouldn't have allowed assignment to __bases__, and the behavior is slightly surprising, but fixing it would be too complicated and there's not enough interest in getting it fixed.
On Feb 6, 2018 12:13 AM, "VA" <rep...@bugs.python.org> wrote: > > VA <d.python.d...@indigo.re> added the comment: > > The use case is a little more complex. > > I have a plugin system, with abstract interfaces. Plugins can't import > each other, but plugins should be able to allowed to depend on another > plugin (using string codes, still no direct imports), and even subclass > another plugin's classes (and override some of their methods). > > In the sample code, A and C would be 2 plugins, and B would be a helper > class (with string code parameters) whose purpose is to make a temporary > bridge between A and C. > A should work standalone. C would use A's code but could reimplement some > of A's methods. B is a internal class that has A and C at hand, and changes > C's __bases__ to point to A. > > I have been suggested other solutions, like using composition (a C > instance would have an "a" field pointing to an A instance) to avoid > inheritance altogether, or using the "type()" function in B.__new__ to > create a custom class inheriting A. > None of these solutions are really satisfying because they prevent C from > using "super(...)" to refer to A methods. > Rebinding __class__ simply does not allow to override methods at all. > > ---------- > > _______________________________________ > Python tracker <rep...@bugs.python.org> > <https://bugs.python.org/issue32768> > _______________________________________ > ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue32768> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
