Question

当我遇到困境时，我一直在练习python。我无法弄清楚如何通过列表循环原始输入（使用while）以生成正确的错误消息。

places_to_visit = {1 : 'London', 2 : 'Rome', 3: 'Amsterdam', 4: 'Paris'}
place = raw_input("where are you travelling to?:")
#gives the cost of travelling to a specific destination
while str(place) != ____:
    place = raw_input("Sorry i did not catch that. please enter your destination again:")

if str(place) == ____:
    def travel_cost(place):
        if place == "London":
            return 2000
        elif place == "Rome":
            return 3000
        elif place == "Amsterdam":
            return 3000
        elif place == "Paris":
            return 5000

任何帮助将不胜感激。感谢

Answer 1

如果您将费用存储在适当的dict中，则可以执行以下操作：

#!/usr/bin/env python
# coding: utf-8

places_with_costs = {"London": 2000, "Rome": 3000, "Amsterdam": 3000, "Paris":5000}

while True:
    place = raw_input("Where are you travelling to?: ")

    if place in places_with_costs:
        print "Your trip is {}.".format(places_with_costs[place])
    else:
        print "Unable to find your destination. Try again."

Answer 2

您可以使用in运算符查看元素是否在序列中

while place not in places_to_visit.values()

在这种情况下，您可以测试他们输入的字符串是否在您dict

的城市列表中

使用原始输入循环遍历列表

2 个答案: