f.model = model
self.year = year
self.odometer_reading = 23
def get_descriptive_name(self):
"""返回整洁的描述信息"""
long_name = str(self.year) + ' ' +self.make + ' ' + self.model
return long_name.title()
def read_odometer(self):
"""打印一条指出汽车里程的信息"""
print("This car has " +str(self.odometer_reading) + " miles on it.")
my_new_car = Car('audi','a4',2017)
print(my_new_car.get_descriptive_name())
my_new_car.read_odometer()
===============================================
2017 Audi A4
This car has 23 miles on it.
#!/usr/bin/env python
class Car():
"""一次模拟汽车的简单尝试"""
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):
"""返回整洁的描述信息"""
long_name = str(self.year) + ' ' +self.make + ' ' + self.model
return long_name.title()
def read_odometer(self):
"""打印一条指出汽车里程的信息"""
print("This car has " +str(self.odometer_reading) + " miles on it.")
def update_odometer(self,mileage):
"""将里程表读数设置为指定的值"""
self.odometer_reading = mileage
my_new_car = Car('audi','a4',2017)
print(my_new_car.get_descriptive_name())
my_new_car.update_odometer(23)
my_new_car.read_odometer()
==============================================
2017 Audi A4
This car has 23 miles on it.
对Car类所做的唯一修改是添加了方法update_odometer()。这个方法接受一个里程值，并将其存储到self.odometer_reading中。
3、继承
编写类时，并非总是从空白开始。如果你要编写的类时另一个现成类的特殊版本，可使用继承。一个类继承另一个类时，它将自动获得另一个类的所有属性和方法；原有的类称为父类，而新类称为子类。子类继承了其父类的所有属性和方法，同时还可以定义自己的属性和方法。
#!/usr/bin/env python
class Car():
"""一次模拟汽车的简单尝试"""
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):
"""返回整洁的描述信息"""
long_name = str(self.year) + ' ' +self.make + ' ' + self.model
return long_name.title()
def read_odometer(self):
"""打印一条指出汽车里程的信息"""
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 cant roll back an odometer!")
def increment_odometer(self,miles):
self.odometer_reading += miles
class ElectricCar(Car):
"""电动车的独特之处"""
def __init__(self,make,model,year):
"""初始化父辈的属性"""
super().__init__(make,model,year)
my_tesla = ElectricCar('tesla','model s',2017)
print(my_tesla.get_descriptive_name())
==========================================
2017 Tesla Model S
4、导入类
#!/usr/bin/env python
from car import Car
my_new_car = Car('audi','a4',2017)
print(my_new_car.get_descriptive_name())
my_new_car.odometer_reading = 23
my_new_car.read_odometer()
=======================================
2017 Audi A4
This car has 23 miles on it