text: """电动汽车类"""
  
  from car import Car
  
  
  class Battery:
      """一次模拟汽车电瓶的简单尝试"""
  
      def __init__(self,battery_size=75):
          """初始化电瓶的属性"""
          self.battery_size = battery_size
  
      def describe_battery(self):
          """打印一条描述电瓶容量的消息"""
          print(f"This car has a {self.battery_size}-kwh battery.")
  
      def get_range(self):
          """打印一条消息，指出电瓶的续航里程"""
          if self.battery_size == 75:
              range = 260
          elif self.battery_size == 100:
              range = 315
  
          print(f"This car can go about {range} miles on a full charge.")
  
  
  class ElectricCar(Car):
      """电动汽车的独特之处"""
      def __init__(self,make,modle,year):
          """
          初始化父类的属性。
          再初始化子类的特殊属性。
          """
          super().__init__(make,modle,year)
          self.battery = Battery()#将实例用作属性
  
      #重写父类方法
      def full_gas_tank(self):
          """电动汽车没有油箱"""
          print("Electric car doesn't need a gas tank!")
  