super在python中有什么用

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有什么区别？

class Child(SomeBaseClass):
    def __init__(self):
        super(Child, self).__init__()

class Child(SomeBaseClass):
    def __init__(self):
        SomeBaseClass.__init__(self)

SomeBaseClass.__init__(self)

super(Child, self).__init__()

表示__init__从Child实例的方法解析顺序（MRO）中的父类调用绑定。

如果实例是Child的子类，则MRO中可能会有另一个父级。

我玩了一下super()，并且认识到我们可以改变呼叫顺序。

例如，我们有下一个层次结构：

 A
   /   B   C
   \ /
    D

在这种情况下，D的mro将是（仅适用于Python 3）：

In [26]: D.__mro__
Out[26]: (__main__.D, __main__.B, __main__.C, __main__.A, object)

In [23]: class A(object): #  or with Python 3 can define class A:
...:     def __init__(self):
...:         print("I‘m from A")
...:  
...: class B(A):
...:      def __init__(self):
...:          print("I‘m from B")
...:          super().__init__()
...:   
...: class C(A):
...:      def __init__(self):
...:          print("I‘m from C")
...:          super().__init__()
...:  
...: class D(B, C):
...:      def __init__(self):
...:          print("I‘m from D")
...:          super().__init__()
...: d = D()
...:
I‘m from D
I‘m from B
I‘m from C
I‘m from A

    A
   / ?
  B ⇒ C
   ? /
    D

In [21]: class A(object):  # or class A:
...:     def __init__(self):
...:         print("I‘m from A")
...:  
...: class B(A):
...:      def __init__(self):
...:          super().__init__()  # or super(B, self).__init_()
...:          print("I‘m from B")
...:   
...: class C(A):
...:      def __init__(self):
...:          super().__init__()
...:          print("I‘m from C")
...:  
...: class D(B, C):
...:      def __init__(self):
...:          super().__init__()
...:          print("I‘m from D")
...: d = D()
...: 
I‘m from A
I‘m from C
I‘m from B
I‘m from D

  A
   / ?
  B ⇐ C
   ? /
    D