class Car():
    """一次模拟汽车的简单尝试"""
    # 初始化描述汽车的属性
    def __init__(self, make, model, year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0
        
    #返回整洁的描述性名称
    def get_descriptive_name(self):
        long_name = str(self.year) + ' ' + self.make + ' ' + self.model
        return long_name.title()
    
    # 打印一条消息，指出汽车的里程
    def read_odometer(self):
        print("This car has " + str(self.odometer_reading) + " miles on it.")
        
    # 将里程表读数设置为指定的值拒绝将里程表往回拨
    def update_odometer(self, mileage):
        if mileage >= self.odometer_reading:
            self.odometer_reading = mileage
        else:
            print("You can't roll back an odometer!")
            
    # 将里程表读数增加指定的量
    def increment_odometer(self, miles):
        self.odometer_reading += miles
        
class Battery():
    """一次模拟电动汽车电瓶的简单尝试"""
    #初始化电瓶的属性
    def __init__(self, battery_size=60):
        self.battery_size = battery_size
        
    #打印一条描述电瓶容量的消息
    def describe_battery(self):
        print("This car has a " + str(self.battery_size) + "-kWh battery.")
    
    #打印一条描述电瓶续航里程的消息
    def get_range(self):
        if self.battery_size == 70:
            range = 240
        elif self.battery_size == 85:
            range = 270
    message = "This car can go approximately " + str(range) + " miles on a full charge."
    print(message)
    
class ElectricCar(Car):
    """模拟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
    def __init__(self, make, model, year):
        super().__init__(make, model, year)
        self.battery = Battery()