python inheritance polymorphism

Inheritance of python

#-*- coding:utf-8 -*- 
class A(object): 
    def __init__(self): 
        print('A: I will definitely execute!!') 

    def fun(self): 
        print('AAAA' ) 

    def fun_A(self): 
        print('This is A alone!!') 
    pass 

class B(object): 
    def __init__(self): 
        print('B: I will definitely execute it!!') 

    def fun (self): 
        print('BBBB') 
    pass 

class C(A,B): 
    def __init__(self): 
        super(C, self).__init__() 
        super(A, self).__init__() 
        # super(). __init__()#python3 above syntax 
        print('C: I will definitely execute!!') 

    def fun(self): 
        super(C, self).fun() 
        super(A, self).fun()
        # super().fun()# python3 and above syntax 
        print('CCCC') 
    pass 

class D(B,A): 
    def __init__(self): 
        super(D,self).__init__() 
        super(B, self). __init__() 
        # super().__init__()# python3 syntax above 
        print('D: I will definitely execute!!') 

    def fun(self): 
        super(D, self).fun() 
        super(B, self).fun() 
        # super().fun()# python3 and above syntax 
        print('DDDD') 
    pass 

f1=C() 
print(C.__mro__)#Show inheritance order, from child to parent 
f1.fun() 
f1.fun_A() 
print('----------------------------') 
f2=D() 
print(D.__mro__)#display Inheritance order, from child to parent 
f2.fun() 
f2.fun_A()

output:

A:我是肯定会执行的！！
B:我是肯定会执行的！！
C:我是肯定会执行的！！
(<class '__main__.C'>, <class '__main__.A'>, <class '__main__.B'>, <type 'object'>)
AAAA
BBBB
CCCC
这是A单独有的！！
---------------------------
B:我是肯定会执行的！！
A:我是肯定会执行的！！
D:我是肯定会执行的！！
(<class '__main__.D'>, <class '__main__.B'>, <class '__main__.A'>, <type 'object'>)
BBBB
AAAA
DDDD
这是A单独有的！！

 

 python 多态

#-*- coding:utf-8 -*-
class animal:
    def run(self):
        pass

class people(animal):
    def run(self):
        print('people is walking!!')

class pig(animal):
    def run(self):
        print('pig is walking!!')

class dog(animal):
    def run(self):
        print('dog is walking!!')

class fun(object):
    def run(self,obj):
        obj.run()

f=fun()#在这种情况下，由animal定义方法名，直接调用fun的方法，实现多态，统一接口
f.run(people())
f.run(pig())
f.run(dog())

输出：

people is walking!!
pig is walking!!
dog is walking!!