Christian Heimes wrote:
Most magic methods are implemented as descriptors. Descriptors only looked up on the type to increase the performance of the interpreter and to simply the C API.
There's also a semantic problem. Since new-style classes are also instances (of class 'type') and you can create subclasses of 'type', if special methods were looked up on instances, it would be ambiguous whether an attribute '__getitem__' on a class was meant to specify the behaviour of the [] operation on its instances, or on the class itself. This problem didn't arise with old-style classes, because classes and instances were clearly separated (i.e. old-style classes were not old-style instances). -- Geg -- http://mail.python.org/mailman/listinfo/python-list
