8.9 实验室：汽车价值（等级）

Question

通过创建属性 purchase_price（int 类型）和输出汽车信息的方法 print_info() 来完成 Car 类。

Ex：如果输入是： 2011年 18000 2018

其中 2011 是汽车的车型年份，18000 是购买价格，2018 是当前年份，然后 print_info() 输出： 车辆信息： 车型年份：2011 购买价格：18000 当前值：5770

注意：print_info() 应该使用三个空格进行缩进。

下面提供的代码

class Car:
    def __init__(self):
        self.model_year = 0
        # TODO: Declare purchase_price attribute
      
        self.current_value = 0

    def calc_current_value(self, current_year):
        depreciation_rate = 0.15
        # Car depreciation formula
        car_age = current_year - self.model_year
        self.current_value = round(self.purchase_price * (1 - depreciation_rate) ** car_age)
    
    # TODO: Define print_info() method to output model_year, purchase_price, and current_value


if __name__ == "__main__":    
    year = int(input()) 
    price = int(input())
    current_year = int(input())
    
    my_car = Car()
    my_car.model_year = year
    my_car.purchase_price = price
    my_car.calc_current_value(current_year)
    my_car.print_info()
    

我尝试了什么，但我不知道我做错了什么。我不断收到“TypeError: print_info() takes 0 positional arguments but 1 was given.”

class Car:
    def __init__(self):
        self.model_year = 0
        # TODO: Declare purchase_price attribute
        self.purchase_price = ''
        self.current_value = 0

    def calc_current_value(self, current_year):
        depreciation_rate = 0.15
        # Car depreciation formula
        car_age = current_year - self.model_year
        self.current_value = round(self.purchase_price * (1 - depreciation_rate) ** car_age)
    
    # TODO: Define print_info() method to output model_year, purchase_price, and current_value
    def print_info():
        print('Car' + "'" + 's', 'information\n')
        print('Model year:', self.model_year)
        print('Purchase price:', self.purchase_price)
        print('Current value:', self.current_value)

if __name__ == "__main__":    
    year = int(input()) 
    price = int(input())
    current_year = int(input())
    
    my_car = Car()
    my_car.model_year = year
    my_car.purchase_price = price
    my_car.calc_current_value(current_year)
    my_car.print_info()

Answer 1

所做的更改：-

def print_info(): -> def print_info(self):

代码：-

class Car:
    def __init__(self):
        self.model_year = 0
        # TODO: Declare purchase_price attribute
        self.purchase_price = ''
        self.current_value = 0

    def calc_current_value(self, current_year):
        depreciation_rate = 0.15
        # Car depreciation formula
        car_age = current_year - self.model_year
        self.current_value = round(self.purchase_price * (1 - depreciation_rate) ** car_age)
    
    # TODO: Define print_info() method to output model_year, purchase_price, and current_value
    def print_info(self):
        print('Car' + "'" + 's', 'information\n')
        print('Model year:', self.model_year)
        print('Purchase price:', self.purchase_price)
        print('Current value:', self.current_value)

if __name__ == "__main__":    
    year = int(input()) 
    price = int(input())
    current_year = int(input())
    
    my_car = Car()
    my_car.model_year = year
    my_car.purchase_price = price
    my_car.calc_current_value(current_year)
    my_car.print_info()

输出：

2011
16000
2019
Car's information

Model year: 2011
Purchase price: 16000
Current value: 4360

Answer 2

10/10

    def print_info(self):
            self.print_info = print(f'Car\'s information:\n   Model year: {self.model_year}\n   Purchase price: {self.purchase_price}\n   Current value: {self.current_value}')