Understanding Python super() with __init__() methods?

Question

I'm trying to understand the use of `super()`. From the looks of it, both child classes can be created, just fine. I'm curious to know about the actual difference between the following 2 child classes. class Base(object):  def __init__(self):   print "Base created"    class ChildA(Base):  def __init__(self):   Base.__init__(self)    class ChildB(Base):  def __init__(self):   super(ChildB, self).__init__()    ChildA() ChildB()

Answer 1

In ChildA, the parent class's __init__ method is explicitly called in the constructor with an argument of self. In ChildB, the super call is syntax sugar for calling the __init__ method of ChildB's parent class with the argument of self. The difference is twofold. First, if the parent class changes, you don't need to change anything the __init__ method of ChildB, but you would need to change the Base.__init__(self) call in ChildA. Secondly, the super() function, uses what is called Method Resolution Order, or mro, in order to properly resolve the method order conflicts that can occur when the class hierarchy is more complex than your simple example. In fact, the super call in your example could be shorted to super().__init__().