car_1.py

# -*- coding: cp936 -*-
# 详细说明见书P144
# 创建一个汽车的类
# 修改属性的值，三种不同的方法

class Car():
    
    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
    
    def get_descriptive_name(self):
        """返回整洁的描述性信息"""
        long_name = str(self.year) + ' ' + self.make + ' ' + self.model
        return long_name.title()
    
    def read_odometer(self):
        """打印出一条指出汽车里程的消息"""
        print("This car has " + str(self.odometer_reading) + " miles on it.")

my_new_car = Car('audi', 'a4', 2016)
print(my_new_car.get_descriptive_name())
my_new_car.read_odometer()

# 方法一：实例中直接修改里程的值
my_new_car = Car('audi', 'a4', 2016)
print("\n" + my_new_car.get_descriptive_name())
my_new_car.odometer_reading = 23
my_new_car.read_odometer()