修改类的属性值

#直接修改属性的值
# -*- coding:utf-8 -*-

class Car():
    def __init__(self,make,model,year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0

    def get_descriptive_name(self):
        long_name = str(self.year) + ‘ ‘ + self.make + ‘ ‘ + self.model
        return long_name.title()

    def read_odometer(self):
        print("This car has " + str(self.odometer_reading) + " miles on it.")


myNewCar = Car(‘audi‘,‘a4‘,2016)
print(myNewCar.get_descriptive_name())
myNewCar.odometer_reading = 23
myNewCar.read_odometer()

#通过方法修改属性的值
# -*- coding:utf-8 -*-

class Car():
    def __init__(self,make,model,year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0

    def get_descriptive_name(self):
        long_name = str(self.year) + ‘ ‘ + self.make + ‘ ‘ + self.model
        return long_name.title()

    def read_odometer(self):
        print("This car has " + str(self.odometer_reading) + " miles on it.")

    def update_odometer(self, mileage):
        self.odometer_reading = mileage

myNewCar = Car(‘audi‘,‘a4‘,2016)
print(myNewCar.get_descriptive_name())
myNewCar.update_odometer(24)
myNewCar.read_odometer()

#通过方法对属性的值进行递增
# -*- coding:utf-8 -*-

class Car():
    def __init__(self,make,model,year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0

    def get_descriptive_name(self):
        long_name = str(self.year) + ‘ ‘ + self.make + ‘ ‘ + self.model
        return long_name.title()

    def read_odometer(self):
        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 can‘t roll back an odometer!")

    def increment_odometer(self,miles):
        self.odometer_reading += miles

myNewCar = Car(‘audi‘,‘a4‘,2016)
print(myNewCar.get_descriptive_name())

myNewCar.update_odometer(23500)
myNewCar.read_odometer()

myNewCar.increment_odometer(8)
myNewCar.read_odometer()