>>> class A(object):
...   def hello(self):
...     print 'hello'
...
>>> class B(object):
...   def hello(self):
...     print ' world!'
...
>>> class C(A, B):
...   pass
...
>>> c = C()
>>> c.hello()
hello
>>> class D(B, A):
...   pass
...
>>> d = D()
>>> d.hello()
 world!
>>>