Question

我有问题！我试图迭代一个列表，检查它是否在里面，如果它在里面进行下一步，如果不是，重复输入，直到用户输入该列表中的一个元素

接下来，我会提供我的代码，请将其中一些列表用于其他目的！我正在使用的是FoodAvaiable。

DictFood = {"pasta":["spaghetti"], "meat":["beef of deer", "sasuage"], "vegetables":["chips", "letucce"], "condiment":["sugar", "salt"], "fruit":["apple", "orange"], "sweet":["chocolate"], "drink":["beer", "water"]}
TypeFood = ["pasta", "fruit", "meat", "vegetables", "condiment", "sweet", "drink"]
DictValue = {"orange":1, "spaghetti":12, "salt":0.2, "chocolate":2, "beef of deer":1, "beer":0.3, "water":0.5, "fish":3, "chips":2, "sugar":0.2, "bread":2, "apple":1, "letucce":1, "sasuage":3}
FoodAvaiable = ["orange", "spaghetti", "salt", "chocolate", "beef of deer", "beer", "water", "fish", "chips", "sugar", "bread", "apple", "letucce", "sasuage"]
x = True

def food_type():
    global user_option_f
    print("What do you want to buy?")
    print(FoodAvaiable)
    user_option_f = input()
    while x == True:
        if user_option_f == FoodAvaiable[0]: #here I have my doubt!! I've tried using "or" to add "FoodAvaibale[1]" and so on, and I got a infinite loop, I've tried "range(len(FoodAvaiable))" didn't worked too
            x == False
            print("You choose {}!".format(user_option_f))
        elif user_option_f != FoodAvaiable:
            print("You choose an element which is not avaiable! Please select one of the list")
            print(FoodAvaiable)
            print("Choose one avaiable")
            input()
    return user_option_f

food_type()

如何让我的user_input_f遍历列表中的元素，检查它是否在内部。

很抱歉，如果之前有人询问，我搜索了很多没有找到任何可以帮助我的事情。先谢谢

Answer 1

你可以使用嵌套的for循环来做到这一点，但正确的方法就是使用'in'运算符。

while True:
    user_input = input('Food: ')
    if user_input in FoodAvailable:
        return user_input
    else:
        print('Choose one of {}'.format(', '.join(FoodAvailable)))

Answer 2

我在一些答案的帮助下设法修复代码（感谢@UnoriginalNick和@StephenRauch）

DictFood = {"pasta":["spaghetti"], "meat":["beef of deer", "sasuage"], "vegetables":["chips", "letucce"], "condiment":["sugar", "salt"], "fruit":["apple", "orange"], "sweet":["chocolate"], "drink":["beer", "water"]}
TypeFood = ["pasta", "fruit", "meat", "vegetables", "condiment", "sweet", "drink"]
DictValue = {"orange":1, "spaghetti":12, "salt":0.2, "chocolate":2, "beef of deer":1, "beer":0.3, "water":0.5, "fish":3, "chips":2, "sugar":0.2, "bread":2, "apple":1, "letucce":1, "sasuage":3}
FoodAvaiable = ["orange", "spaghetti", "salt", "chocolate", "beef of deer", "beer", "water", "fish", "chips", "sugar", "bread", "apple", "letucce", "sasuage"]


def food_type():
    x = True
    global user_option_f
    print("What do you want to buy?")
    print(FoodAvaiable)
    while x == True:
        user_option_f = input()
        if user_option_f in FoodAvaiable:
            x = False
            print("You choose {}!".format(user_option_f))
        elif user_option_f not in FoodAvaiable:
            print("You choose an element which is not avaiable! Please select one of the list")
            print(FoodAvaiable)
            print("Choose one avaiable")
            input()
    return user_option_f

food_type()

获取定义之外的输入给了我一个错误，所以我最终在def中编写它并对elif进行一些调整，也许我应该使用else而不是，但是因为这样看似稳定，我＆＃39;保持它

迭代列表检查用户的输入是否在列表中

2 个答案: