Question

我看不出我搞砸了。我刚刚在2天前启动了Python，这是来自Codecademy的问题。

错误

trip_cost('Pittsburgh', 4) raised an error: coercing to Unicode: need string or buffer, int found

代码

def hotel_cost(nights):
    return 140 * nights

def plane_ride_cost(city):
    if city == "Charlotte":
        return 183
    elif city == "Tampa":
        return 220
    elif city == "Pittsburgh":
        return 222
    else:
        return 475

def rental_car_cost(days):
    cost = days * 40
    if days >= 7:
        cost = cost - 50
    elif days >= 3:
        cost = cost - 20
    return cost

def trip_cost(city, days):
    city = raw_input("What city are you travelling to?")
    days = raw_input("How many days are you staying?")
    total_cost = hotel_cost(days) + plane_ride_cost(city) + rental_car_cost(days)
    print total_cost

Answer 1

trip_cost()忽略传递给它的参数。对其中的raw_input()的调用返回字符串（在Python 2.x中），但是您的其他函数期望将整数传递给它们。请改用input()功能。

Answer 2

试试这个：

def hotel_cost(nights):
    return 140 * nights

def plane_ride_cost(city):
    if city == "Charlotte":
        return 183
    elif city == "Tampa":
        return 220
    elif city == "Pittsburgh":
        return 222
    else:
        return 475

def rental_car_cost(days):
    cost = days * 40
    if days >= 7:
        cost = cost - 50
    elif days >= 3:
        cost = cost - 20
    return cost

def trip_cost(city, days):
    city = raw_input("What city are you travelling to?")
    days = raw_input("How many days are you staying?")
    total_cost = hotel_cost(int(days)) + plane_ride_cost(city) + rental_car_cost(int(days))
    print total_cost

if __name__ == '__main__':
    trip_cost(None, None)

解释一下： raw_input会给你一个字符串。如果您要对从raw_input获得的值进行算术运算，则需要将其转换为整数。

此外，如果您尝试从命令行运行此操作，则需要输入最后两行。

你真的应该替换：

def trip_cost(city, days)

与

def trip_cost()

因为您没有从传递给方法的参数中填充city和days值，而是使用raw_input从控制台获取这些值。

如果你这样做，那么改变：

trip_cost(None, None)

到

trip_cost()

所有这些都说，这就是我最终会重写它的方式：

def hotel_cost(nights):
    return 140 * nights

def plane_ride_cost(city):
    if city == "Charlotte":
        return 183
    elif city == "Tampa":
        return 220
    elif city == "Pittsburgh":
        return 222
    else:
        return 475

def rental_car_cost(days):
    cost = days * 40
    if days >= 7:
        cost = cost - 50
    elif days >= 3:
        cost = cost - 20
    return cost

def trip_cost():
    city = raw_input("What city are you travelling to?")
    days = raw_input("How many days are you staying?")
    total_cost = hotel_cost(int(days)) + plane_ride_cost(city) + rental_car_cost(int(days))
    print total_cost

if __name__ == '__main__':
    trip_cost()

输出如下：

(cost)macbook:cost joeyoung$ python cost.py 
What city are you travelling to?Pittsburgh
How many days are you staying?4
922

PYTHON trip_cost（'Pittsburgh'，4）引发了一个错误：强制转换为Unicode：需要字符串或缓冲区，找到int

2 个答案: