tomer filiba wrote: > b=B() # error, A.__init__ expects an instanc of A > > why is this kind of type-checking enforced by the language?
Since type-class unification, there is no clear boundary between built-in and user-defined classes. Any class can potentially add C-level data to its instances and have methods implemented in C that operate on it. If you were allowed to pass any object to any method, there would be a danger of crashing the interpreter. > what this code does is basically changing the __mro__ of the object. had > __mro__ been mutable, it would all be simpler. Being able to change the mro after class creation would lead to similar problems. -- Greg _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
