Shouldn't __metaclass__ force the use of a metaclass in Python?

Question

I\'ve been trying to learn about metaclasses in Python. I get the main idea, but I can\'t seem to activate the mechanism. As I understand it, you can specify M to be as the

Answer 1

This works as you expect in Python 2.6 (and earlier), but in 3.0 metaclasses are specified differently:

class ArgMeta(metaclass=M): ...