类的继承

# # python3默认是广度优先，先找自己的方法或属性，如果没，往父类找
# class Animal:
#     def __init__(self):
#         print('执行Animal.__init__')
#         self.func()
#
#     def eat(self):
#         print('%s eating' %self.name)
#
#     def drink(self):
#         print('%s drinking' % self.name)
#
#     def func(self):
#         print('Animal.func')
#
# class Dog(Animal):
#     def guard(self):
#         print('guarding')
#
#     def func(self):                     # 重写父类方法，派生方法
#         print('Dog.func')
#
# class Bird(Animal):
#     def __init__(self, name):
#         # Animal.__init__(self)          # 父类名.方法名 需要自己传self参数
#         super().__init__()           # super().方法名 不需要自己传self,这是新式类
#         self.name = name             # 派生属性
#     def lay(self):
#         print('laying')
#
#
# # print(Dog.__bases__)       # 查看父类
# # dog = Dog()                # 这里Dog没有init方法，会调用父类的init
# bird = Bird('ssss')
# # bird.lay()
# bird.drink()
# # bird.eat()

 

# 新式类默认广度优先，经典类是深度优先
# super 只在python3中存在
# super的本质 ：不是单纯找父类 而是根据调用者的节点位置的广度优先顺序来的


class A:
    def func(self):
        print('A')


class B(A):
    pass
    def func(self):
        super().func()
        print('B')

class C(A):
    pass
    def func(self):
        super().func()
        print('C')


class D(B, C):
    pass
    def func(self):
        super().func()
        print('D')

d = D()
d.func()
print(B.mro())