类的操作-汽车类

#author = ‘zhanghang‘#coding :-*- utf-8 -*-

class Car():#定义car类    def __init__(self,make,model,year):        "初始化描述汽车的属性"        self.make = make        self.model = model        self.year = year        self.odometer_reading = 0 #设置里程属性初始值为0 ，无需在init中设置形参    def get_describe_name(self):        "返回整洁的汽车描述信息"        long_name = str(self.year) + ‘ ‘ + self.make + ‘ ‘ + self.model        return long_name.title()    def update_odometers(self,miles):        "通过方法修改属性odometer_reading的值"        self.odometer_reading += miles    def reading_odometer(self):        "读取汽车的里程"        print("This car has " + str(self.odometer_reading) + " miles on it.")

class Battery():    "电瓶具有自己的属性和方法，单独做一个类"    def __init__(self,battery_size):        self.battery_size = battery_size    def upgrade_battery(self):        if self.battery_size<85:            self.battery_size = 85    def describe_battery(self):        print("This EletricCar‘s battery is " + str(self.battery_size) + "-kwh")    def get_range(self):        if self.battery_size <= 70:            range = 240        else:            range = 280        message = "This car can go approximately " + str(range)        message += " miles on a full charge"        print(message)

class ElectricCar(Car):#电动汽车继承汽车类    "子类ElectricCar继承父类Car"    def __init__(self,make,model,year):        super().__init__(make,model,year) #初始化父类的属性        self.battery = Battery(70) #实例用作属性    def get_describe_name(self):        "假设子类ElectricCar与父类Car的描述不一致，则在子类中重新定义同名方法,Python将不考虑父类中该方法"        print("The ElectricCar‘s type is " + str(self.year) + ‘ ‘ + self.make + ‘ ‘ + self.model)

my_car = Car(‘audi‘,‘a4‘,2016)#根据类创建实例print(my_car.get_describe_name())my_car.update_odometers(2000)my_car.reading_odometer()

my_eletricCar = ElectricCar(‘aima‘,‘e1‘,2017)#根据子类创建实例my_eletricCar.get_describe_name()my_eletricCar.update_odometers(2000)my_eletricCar.reading_odometer()my_eletricCar.battery.describe_battery()my_eletricCar.battery.get_range()my_eletricCar.battery.upgrade_battery() #通过类Battery()里的upgrade_battery将battery更改为85kwhmy_eletricCar.battery.describe_battery() #my_eletricCar.battery传值到类Battery() 调用Battery()的方法describe_batterymy_eletricCar.battery.get_range()

运行结果：2016 Audi A4This car has 2000 miles on it.The ElectricCar‘s type is 2017 aima e1This car has 2000 miles on it.This EletricCar‘s battery is 70-kwhThis car can go approximately 240 miles on a full chargeThis EletricCar‘s battery is 85-kwhThis car can go approximately 280 miles on a full charge