PY3多继承

__author__ = "Alex Li"

class A:
    def __init__(self):
        print("A")
class B(A):
    pass
    #def __init__(self):
    #     print("B")
class C(A):
    pass
    #def __init__(self):
    #     print("C")
class D(B,C):#继承了B里面的构造函数之后，就不会再走C了
    pass
    #def __init__(self):
         #print("D")

#py3的构造函数是广度优先，D->B->C->D
obj = D()