最常见的就是初始化方法__init__()
python中类的初始化方法是__init__(),因此父类子类的初始化方法都是这个,如果子类不实现这个函数,初始化时调用父类的初始化函数,如果子类实现这个函数,就覆盖了父类的这个函数,既然继承父类,就要在这个函数里显式调用一下父类的__init__(),这跟C++,jAVA不一样,他们是自动调用父类初始化函数的。
调用父类函数有以下方法:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | # -*- coding:utf-8 -*-
class Animal():
def __init__( self , name):
self .name = name
def saySomething( self ):
print ( "I am " + self .name)
class Dog(Animal):
def __init__( self , name):
super ().__init__(name)
def saySomething( self ):
print ( "I am " + self .name + ", and I can bark" )
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1.直接写类名调用: parent_class.parent_attribute(self)
2.用 super(type, obj).method(arg)方法调用:super(child_class, child_object).parent_attribute(arg) 【不需要写self】
3.在类定义中调用本类的父类方法,可以直接 super().parent_method(arg) 【个人推崇这种写法】
样例如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 | # -*- coding:utf-8 -*-
# file_name: python_class_inheritance_example.py
class Animal():
def __init__( self , name):
self .name = name
def saySomething( self ):
print ( "I am " + self .name)
class Dog(Animal):
def __init__( self , name):
super ().__init__(name)
def saySomething( self ):
print ( "I am " + self .name + ", and I can bark" )
def animal_say_1( self ):
# 子类调用父类的方法
# 方式1
super (Dog, self ).saySomething()
def animal_say_2( self ):
# 方式2 [推荐]
super ().saySomething()
def animal_say_3( self ):
# 方式3
Animal.saySomething( self )
if __name__ = = "__main__" :
dog = Dog( "Blake" )
dog.saySomething()
dog.animal_say_1()
dog.animal_say_2()
dog.animal_say_3()
# 子类对象调用被覆盖的父类方法
super (Dog, dog).saySomething()
'''
输出结果如下:
python python_class_inheritance_example.py
I am Blake, and I can bark
I am Blake
I am Blake
I am Blake
I am Blake
'''
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