Python12（接口继承，子类调用父类，多态）

接口继承：

基类不用实现内部逻辑，只是为了规范子类，可以用abc模块中以添加装饰器的方式实现

import abc
class All_file(metaclass=abc.ABCMeta):

    @abc.abstractmethod
    def read(self):
        pass

    @abc.abstractmethod
    def write(self):
        pass

class Disk(All_file):
    def read(self):
        print("Disk read")
    def write(self):
        pass
class Cdrom(All_file):
    def read(self):
        pass
    def write(self):
        pass

m1 = Disk()
m1.read()
m1.write()

在子类中调用父类方法：

class Vehiale:
    country = "China"
    def __init__(self,name,speed,load,power):
        self.name = name
        self.speed = speed
        self.load = load
        self.power = power

    def run(self):
        print("kaidongla")

class Subway(Vehiale):
    def __init__(self,name,speed,load,power,line):
        Vehiale.__init__(self,name,speed,load,power)
        self.line = line
    def show_info(self):
        print(self.speed,self.line,self.load,self.name,self.power)
    def run(self):
        Vehiale.run(self)
        print("%s %s 线,开动啦" %(self.name,self.line))

line13=Subway("100m/s",13,1000,"北京地铁","电")
line13.show_info()
line13.run()

多态：

不同的实例可以去调用同一个方法，但实现的效果不同。

class H2O:
    def __init__(self,name,temperature):
        self.name = name
        self.temperature = temperature
    def turn_ice(self):
        if self.temperature < 0:
            print('[%s]温度太低结冰了'%self.name)
        elif self.temperature > 0 and self.temperature < 100:
            print('[%s]液化成水'%self.name)
        elif self.temperature>100:
            print('[%s]温度太高变成水蒸气了'%self.name)

class Water(H2O):
    pass
class Ice(H2O):
    pass
class Steam(H2O):
    pass



w1 = Water('水',25)
i1 = Ice('冰',-20)
s1 = Steam('蒸汽',300)

# w1.turn_ice()
# i1.turn_ice()
# s1.turn_ice()
#多态反映的是一种运行时候的状态
def func(obj):
    obj.turn_ice()

func(w1)
func(i1)
func(s1)