一、指名道姓的方式,不依赖于继承
示例代码如下:
1 class Hero: 2 def __init__(self, nick_name, life_value, aggresivity): 3 self.nick_name = nick_name 4 self.life_value = life_value 5 self .aggresivity = aggresivity 6 7 def attack(self, enemy): 8 enemy.life_value -= self.aggresivity 9 10 11 class Garen(Hero): 12 camp = 'Demacia' 13 14 def attack(self, enemy): 15 Hero.attack(self, enemy) 16 print('from Garen class') 17 18 19 class Riven(Hero): 20 camp = 'Noxus' 21 22 23 g1 = Garen('草丛伦', 100, 30) 24 r1 = Riven('锐雯雯', 80, 50) 25 g1.attack(r1) 26 print(r1.life_value) 27 28 结果为: 29 30 31 from Garen class 32 50
从以上结果可以看出,即执行了自己的特有方法,又执行了父类中继承的方法
想为草丛伦增加一个weapon私有属性,代码如下:
1 class Hero: 2 def __init__(self, nick_name, life_value, aggresivity): 3 self.nick_name = nick_name 4 self.life_value = life_value 5 self .aggresivity = aggresivity 6 7 def attack(self, enemy): 8 enemy.life_value -= self.aggresivity 9 10 11 class Garen(Hero): 12 camp = 'Demacia' 13 14 def __init__(self, nick_name, life_value, aggresivity, weapon): 15 self.nick_name = nick_name 16 self.life_value = life_value 17 self.aggresivity = aggresivity 18 self.weapon = weapon 19 20 def attack(self, enemy): 21 Hero.attack(self, enemy) 22 print('from Garen class') 23 24 25 class Riven(Hero): 26 camp = 'Noxus' 27 28 29 g1 = Garen('草丛伦', 100, 30) 30 r1 = Riven('锐雯雯', 80, 50) 31 g1.attack(r1) 32 print(r1.life_value) 33 34 结果报错: 35 36 Traceback (most recent call last): 37 File "C:/Users/xu516/PycharmProjects/Python全栈开发/第三模块/面向对象编程/12 在子类中重用父类的属性.py", line 31, in <module> 38 g1 = Garen('草丛伦', 100, 30) 39 TypeError: __init__() missing 1 required positional argument: 'weapon'
报错提示缺少一个weapon位置参数,加上位置参数就可以实例化成功了,
但是发现了重复代码,怎样减少重复代码呢,可以使用
1 Hero.__init__(self, nick_name, life_value, aggresivity)
二、super()方法,依赖继承
1 super(Garen, self).attack(enemy)
1 super().__init__(nick_name, life_value, aggresivity)
三、super也会按照mro顺序区查找属性,
示例代码如下:
1 class A: 2 def f1(self): 3 print('from A') 4 super().f1() 5 6 class B: 7 def f1(self): 8 print('from B') 9 10 class C(A,B): 11 pass 12 13 print(C.mro()) 14 15 c = C() 16 c.f1() 17 18 结果为: 19 20 [<class '__main__.C'>, <class '__main__.A'>, <class '__main__.B'>, <class 'object'>] 21 from A 22 from B
可以看出,super并没有去找父类,而是安装mro顺序查找