Py003-01-03子类使用父类属性和方法

M03

子类使用父类属性和方法

指名道姓方式(不依赖继承)

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class Hero:
    def __init__(self, nickname, life_value, aggresivity):
        self.nickname = nickname
        self.life_value = life_value
        self.aggresivity = aggresivity

    def attack(self, enemy):
        enemy.life_value = self.aggresivity


class AX(Hero):
    camp = '斧王'

    def attack(self, enemy):
        Hero.attack(self,enemy)
        print('from Garen Class')

ax = AX('axe',100,50)
enemy = Hero('xxx',100,40)
ax.attack(enemy) # 50

子类想要个武器

很重复的写法

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class AX(Hero):
    camp = '斧王'
    def __init__(self, nickname, life_value, aggresivity,weapon):
        self.nickname = nickname
        self.life_value = life_value
        self.aggresivity = aggresivity
        self.weapon = weapon
    def attack(self, enemy):
        Hero.attack(self,enemy)
        print('from Garen Class')

ax = AX('axe',100,50,'金箍棒')

继续指名道姓

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# 子类有武器 指名道姓
class AX(Hero):
    camp = '斧王'
    def __init__(self, nickname, life_value, aggresivity,weapon):
        Hero.__init__(self, nickname, life_value, aggresivity)
        self.weapon = weapon
    def attack(self, enemy):
        Hero.attack(self,enemy)
        print('from Garen Class')

ax = AX('axe',100,50,'金箍棒')
print(ax.__dict__)

在子类派生出的新的方法中重用父类的方法，有两种方式

  • 指名道姓(不依赖继承)
  • super() (依赖继承)

调用方法

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class AX(Hero):
    camp = '斧王'
    def attack(self, enemy):
        # Hero.attack(self,enemy)
        super(AX,self).attack(enemy)
        print('from Garen Class')

使用父类的初始化方法

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# super
class AX(Hero):
    camp = '斧王'
    def __init__(self, nickname, life_value, aggresivity,weapon):
        # 指名道姓
        # Hero.__init__(self, nickname, life_value, aggresivity)
        # python2中
        super(AX,self).__init__(nickname, life_value, aggresivity) 
        # python3
        super().__init__(nickname, life_value, aggresivity) 
        self.weapon = weapon
    def attack(self, enemy):
        Hero.attack(self,enemy)
        print('from Garen Class')

ax = AX('axe',100,50,'金箍棒')
# print(ax.__dict__)

依赖继承的一道恶心的题

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class A:
    def f1(self):
        print('from a')

class B:
    def f1(self):
        print('from b')

class C(A,B):
    pass

print(C.mro()) # C A B Object

再看

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class A:
    def f1(self):
        print('from a')
        super().f1()

class B:
    def f1(self):
        print('from b')

class C(A,B):
    pass

c = C()
c.f1() 

结果：
from a
from b

C是依赖于继承的 所以会参照 C的mro列表查找 属性和方法