Yes. But, if you prefer a longer answer:
Class B inherits from class A. When implementing B's __init__ function, we may call A's init by writing:
super(B, self).__init__(arguments of A's __init__)
Is it really necessary? After all, in C++ or Java the constructor of base class is called automatically, so shouldn't it be called automatically in Python as well?
The point is that __init__ is not a constructor. Python objects are constructed with __new__. __init__ is used to initialize an object with concrete values, either defaults or passed as __init__'s parameters.
Need more details? Read Python docs at http://docs.python.org/2/reference/datamodel.html#object.__new__