gistfile1.py

>>> class Mcl(type): pass

>>> class A: __metaclass__ = Mcl

>>> class B:
	class __metaclass__(type): pass

	
>>> class C:
	class __metaclass__(type): pass

	
>>> a, b, c = A(), B(), C()
>>> def roundtrip(obj):
	from pickle import dumps, loads
	s = dumps(obj)
	return loads(s)

>>> roundtrip(a)
<__main__.A object at 0x011C38F0>
>>> roundtrip(b)
<__main__.B object at 0x011AA4B0>
>>> roundtrip(c)
<__main__.C object at 0x011AAD50>