>>> class A:
...   def method (self): print 'a'
...
>>> class B(A): #overrides A.method
...   def method (self): print 'b'
...
>>> a = A()
>>> b = B()
>>> a.method ()
a
>>> b.method ()
b
>>> class C(A): pass #doesn't override A.method
...
>>> c = C()
>>> c.method ()
a