2020.1.12

102.(2)
class Car():
    
    def __init__(self , make , model , year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0
        
    def get_descriptive_name(self):
        long_name = str(self.year) + ' ' + self.make + ' ' + self. model
        return long_name.title()
    
    def read_odometer(self):
        print("This car has " + str(self.odometer_reading) + "miles on it.")
        
    def update_odometer(self , mileage):
        if mileage >= self.odometer_reading:
            self.odometer_reading = mileage
        else:
            print("You can't roll back an odometer!")
    
    def increment_odometer(self , miles):
        self.odometer_reading += miles 
        
class ElectricCar(Car):
    '''Represent aspects of a car, specific to electric vehicles.'''
    
    def __init__(self , make ,model ,year):
        """
        电动汽车的独特之处
        初始化父类的属性，再初始化电动汽车特有的属性
        """
        super().__init__(make ,model ,year)
        self.battery_size = 70       # 添加了新属性self.battery_size
                                  # 这个属性子类所有实例都包含，但所有Car实例都不包含        
    def describe_battery(self):
        '''打印一条描述电瓶容量的消息'''
        print("This car has a " + str(self.battery_size) + "-kwh battery.")
     
    def read_odometer(self):      # 可以建立一个和父类相同的方法，进行重写
        print("This car doesn't need a gas tank!")
    
my_tesla = ElectricCar('tesla' , 'model s' , 2016)     # 创建一个实例
print(my_tesla.get_descriptive_name())     # 子类可以调用父类的方法
my_tesla.describe_battery()           #调用子类中的方法
my_tesla.read_odometer()        # 直接调用和父类相同的方法，系统默认子类继承的方法

来源：CSDN

作者：weixin_45707364

链接：https://blog.csdn.net/weixin_45707364/article/details/103943067