Python - 面向对象编程 - super() （下）

from threading import Thread
class MyThread(Thread):
    def __init__(self, name):
        # 1、实现子类独有功能
        print("子类线程 %s" % name)
        # 2、需要依赖父类方法完成其他功能
        super().__init__(name=name)

# 多继承
class Animal:
    def __init__(self, animalName):
        print(animalName, 'is an animal.')
# Mammal 继承 Animal
class Mammal(Animal):
    def __init__(self, mammalName):
        print(mammalName, 'is a mammal.')
        super().__init__(mammalName)
# CannotFly 继承 Mammal
class CannotFly(Mammal):
    def __init__(self, mammalThatCantFly):
        print(mammalThatCantFly, "cannot fly.")
        super().__init__(mammalThatCantFly)
# CannotSwim 继承 Mammal
class CannotSwim(Mammal):
    def __init__(self, mammalThatCantSwim):
        print(mammalThatCantSwim, "cannot swim.")
        super().__init__(mammalThatCantSwim)
# Cat 继承 CannotSwim 和 CannotFly
class Cat(CannotSwim, CannotFly):
    def __init__(self):
        print('I am a cat.');
        super().__init__('Cat')
# Driver code
cat = Cat()
print('')
bat = CannotSwim('Bat')
# 输出结果
I am a cat.
Cat cannot swim.
Cat cannot fly.
Cat is a mammal.
Cat is an animal.
Bat cannot swim.
Bat is a mammal.
Bat is an animal.

class A:
    def __init__(self):
        self.n = 2
    def add(self, m):
        # 第四步
        # 来自 D.add 中的 super
        # self == d, self.n == d.n == 5
        print('self is {0} @AAA.add'.format(self))
        self.n += m
        # d.n == 7
class C(A):
    def __init__(self):
        self.n = 4
    def add(self, m):
        # 第三步
        # 来自 B.add 中的 super
        # self == d, self.n == d.n == 5
        print('self is {0} @CCC.add'.format(self))
        # 等价于 suepr(C, self).add(m)
        # self 的 MRO 是 [D, B, C, A, object]
        # 从 C 之后的 [A, object] 中查找 add 方法
        super().add(m)
        # 第五步
        # d.n = 7
        self.n += 4
        # d.n = 11
class B(A):
    def __init__(self):
        self.n = 3
    def add(self, m):
        # 第二步
        # 来自 D.add 中的 super
        # self == d, self.n == d.n == 5
        print('self is {0} @BBB.add'.format(self))
        # self 的 MRO 是 [D, B, C, A, object]
        # 从 B 之后的 [C, A, object] 中查找 add 方法
        # 从 C 找 add 方法
        super().add(m)
        # 第六步
        # d.n = 11
        self.n += 3
        # d.n = 14
class D(B, C):
    def __init__(self):
        self.n = 5
    def add(self, m):
        # 第一步
        print('self is {0} @DDD.add'.format(self))
        # self 的 MRO 是 [D, B, C, A, object]
        # 从 D 之后的 [B, C, A, object] 中查找 add 方法
        # 从 B 找 add 方法
        super().add(m)
        # 第七步
        # d.n = 14
        self.n += 5
        # self.n = 19
d = D()
d.add(2)
print(d.n)

self is <__main__.D object at 0x10c14a190> @DDD.add
self is <__main__.D object at 0x10c14a190> @BBB.add
self is <__main__.D object at 0x10c14a190> @CCC.add
self is <__main__.D object at 0x10c14a190> @AAA.add
19

class D(B, C):          class B(A):            class C(A):             class A:
    def add(self, m):       def add(self, m):      def add(self, m):       def add(self, m):
        super().add(m)  1.--->  super().add(m) 2.--->  super().add(m)  3.--->  self.n += m
        self.n += 5   <------6. self.n += 3    <----5. self.n += 4     <----4. <--|
        (14+5=19)               (11+3=14)              (7+4=11)                (5+2=7)