Lennart Regebro wrote: > 1. A() < B() will call A.__lt__(B) which will return NotImplemented. > 2. which will mean that Python calls B.__ge__(A) > 3. Which B implements by doing A < B > 4. Start over at 1. > > > Have I missed something, or is this recipe incomplete by not handling > the NotImplemented case? If it is, I think the recipe should be > changed to something that handles it.
I tested both the recipe linked from the docs and Raymond's shorter recipe at http://code.activestate.com/recipes/576685/ and sure enough both suffer from infinite recursion if the root method returns NotImplemented when two of those items are being compared. However, returning NotImplemented generally implies that A and B are *different* classes, so I think this is more of a theoretical problem than a practical one. Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia --------------------------------------------------------------- _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
