python3面向对象--python3中的抽象类和抽象方法，ABC，abstractmethod

蔚落 2022-11-18 10:47 236阅读 0赞

**内容简介：**

和Java一样，Python语言支持抽象类。抽象类用于被继承，而不能被实例化。  
抽象类至少有一个抽象方法。所谓抽象方法，在抽象类中，只有声明，没有具体实现，具体实现必须在子类中，或者说，子类需要实现抽象类中的抽象方法。

**举例：**

Persion是抽象类，play是抽象方法；

Boy和Girl是具体类。

#!/usr/bin/python3
    # -*- coding: UTF-8 -*-
    
    from abc import ABC, abstractmethod
    
    
    #Persion类
    class Persion(ABC):
        __age = 1;
        __sex = True; #True:男； False：女
    
        # def __init__(self,age_param,sex_param):
        #     print("constructor2");
        #     self.__age = age_param;
        #     self.__sex = sex_param;
    
        def getAge(self):
            return self.__age;
        def getSex(m):
            return m.__sex;
        def sayHello(self):
            print("hello world!");
        def __printHi(self):
            print("Hi !!!");
    
        @abstractmethod
        def play(self):
            pass
    
    class Boy(Persion):
        __name = '';
        def setName(self,name):
            self.__name = name;
        def getName(self):
            return self.__name;
    
        def play(self):
            print("I am boy, play game!");
    
    class Girl(Persion):
        __name = '';
        def setName(self,name):
            self.__name = name;
        def getName(self):
            return self.__name;
    
        def play(self):
            print("I am girl,play star!");
    
    #error：Traceback (most recent call last):
    #  File "AbsPersion.py", line 50, in <module>
    #    p = Persion();
    #TypeError: Can't instantiate abstract class Persion with abstract methods play
    
    #p = Persion(); 
    #p.getName();
    
    boy = Boy();
    boy.play();
    
    girl = Girl();
    girl.play();

运行结果：

> python3 AbsPersion.py
> 
> I am boy, play game!
> 
> I am girl,play star!

**说明：**

**使用ABC作为抽象类的基类，用@abstractmethod对抽象方法进行注解。**

而对于下面的代码，就会出错：

> p = Persion();  
> p.getName();

错误提示：

> Traceback (most recent call last):
> 
> File "AbsPersion.py", line 50, in <module>
> 
> p = Persion();
> 
> TypeError: Can't instantiate abstract class Persion with abstract methods play

**即不能实例化一个带有抽象方法play的抽象类Persion。**

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