day_20（继承）

Posted 2020-11-21 molieren

class Animal:
    def __init__(self, name):
        self.name = name

    def eat(self):
        print(‘%s吃‘ % self.name)

    def drink(self):
        print(‘%s喝‘ % self.name)

    def pull(self):
        print(‘%s拉‘ % self.name)

    def sow(self):
        print(‘%s撒‘ % self.name)

    def sleep(self):
        print(‘%s睡‘ % self.name)


class Cat(Animal):

    def call(self):
        print(‘喵喵叫‘)


class Dog(Animal):

    def call(self):
        print(‘汪汪叫‘)


class Chook:
    def call(self):
        print(‘大爷,来玩呀....‘)


cat1 = Cat(‘阿花‘)
cat1.eat()
cat1.drink()
chook1 = Chook()
chook1.call()

继承:子类继承父类的一切.
class Cat(Animal)
Animal 叫做父类,也叫作基类.
Cat 叫做子类,也叫作派生类.

class Animal:
    nickname = ‘动物‘
    def __init__(self, name, age, sex):
        self.name = name
        self.age = age
        self.sex = sex

    def eat(self):
        print("%s在吃东西" % self.name)
class Person(Animal):
    pass
class Dog(Animal):
    pass
class Cat(Animal):
    pass
p1 = Person(‘太白‘,25,‘男‘)
p1.eat()
dog1 = Dog(‘日天‘,6,‘公‘)
dog1.eat()
print(p1.nickname)
print(Person.nickname)

# 继承最大的特点节省代码.与其他类发生关联.

# 为什么子类能找到父类的所有?? 存在父类指针的概念
# 类名,对象都可以找到父类的所有方法.

#python3x   python2x
#python3x 类默认都继承object,继承object类的类叫做新式类.
#python2x 类默认什么不都继承,不继承object的类叫做经典类.如果在python2x中,你让他继承object类,就变成新式类了.

#继承去分:
# 单继承,多继承.
#单继承: 查询顺序一直向上(新式类,经典类一样.)

# class Animal:
#     nickname = ‘动物‘
#
#     def __init__(self, name, age, sex):
#         self.name = name
#         self.age = age
#         self.sex = sex
#
#     def eat(self):
#         print("%s在吃东西" % self.name)
#
#
# class Person(Animal):
#
#     def speek(self):
#         print(‘%s可以用语言交流‘ % self.name)
#
#
# class Brid(Animal):
#
#     def __init__(self, name, age, sex, wing):  # self = b1 对象空间
#         # Animal.__init__(self,name,age,sex)  # 第一种 如何在子类中执行父类方法
#         super(Brid,self).__init__(name, age, sex)  # 第二种  如何在子类中执行父类方法
#         self.wing = wing
#
#     def eat(self, food):
#         super().eat()
#         print(‘%s吃%s‘ % (self.name, food))
#
#     def bite(self):
#         print(‘%s可以啄人‘ % self.name)


# p1 = Person(‘太白‘,25,‘男‘)
# print(p1.nickname)

b1 = Brid(‘鹦鹉‘, 12, ‘母‘, ‘大翅膀‘)
b1.eat(‘小米‘)
# print(b1.__dict__)
# b1.eat(‘小米‘)
# def func1(y,z,w):
#     print(666)
# def func(x,y,z,w):
#     func1(y,z,w)
# func(1,2,3,4)
# 在子类中,执行父类的方法
# Animal.__init__(self,name,age,sex)  # 第一种
#用这种: super().__init__(name, age, sex)      # 第二种  完整的写法 super(Brid,self).__init__(name, age, sex) 不提倡

# 多继承:
# 新式类 : 广度优先
# class A:
#     def func(self):
#         print(‘A‘)
#
# class B(A):
#
#     def func(self):
#         print(‘B‘)
#
# class C(A):
#     def func(self):
#         print(‘C‘)
#
# class D(B):
#     def func(self):
#         print(‘D‘)
# class E(C):
#     def func(self):
#         print(‘E‘)
#
# class F(D,E):
#     def func(self):
#         print(‘F‘)
#
# d = F()
# d.func()
# print(F.mro())       # F.mro()可以查看继承执行顺序

# 经典类 : 深度优先
# class A:
#     def func(self):
#         print(‘A‘)
#
# class B(A):
#
#     def func(self):
#         print(‘B‘)

# class C(A):
#     def func(self):
#         print(‘C‘)

# class D(B,C):
#
#     def func(self):
#         print(‘D‘)
#
# d = D()
# d.func()