跳出 while 循环

Question

shoppingList = [('Carrot',2), ('Onion',1), ('Tomato',3)]
amountGiven = 12
for item, price in shoppingList:

    openMenu = True
    while openMenu:
        costumerPick = input('Please choose item from the shoppingList\n')

        if costumerPick == 'Carrot':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven - price

            
        elif costumerPick == 'Onion':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven -price
            
        elif costumerPick == 'Tomato':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven - price

我想在客户选择其中一个选项后打破循环

Answer 1

看来您有 boolean openMenu并且只有在openMenu = True时才进入 while 循环。

因此，解决这个问题的一种方法是在每个条件语句之后设置openMenu = False 。

你将会拥有：

openMenu = True
    while openMenu:
        costumerPick = input('Please choose item from the shoppingList\n')

        if costumerPick == 'Carrot':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven - price
            openMenu = False

            
        elif costumerPick == 'Onion':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven -price
            openMenu = False
            
        elif costumerPick == 'Tomato':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven - price
            openMenu = False

但是，您似乎并不真的需要 while 循环，因为您的 for 循环遍历了 shoppingList 中的所有元素。

Answer 2

我真的不明白你的问题。 如果你想从 while 循环中中断，当满足特定条件时，使用'break'语句。

shoppingList = [('Carrot',2), ('Onion',1), ('Tomato',3)]
amountGiven = 12

for item, price in shoppingList:
    openMenu = True
    while openMenu:
        costumerPick = input('Please choose item from the shoppingList\n')

        if costumerPick == 'Carrot':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven - price
            break

        elif costumerPick == 'Onion':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven -price
            break
        
        elif costumerPick == 'Tomato':
            print('That would be: ${}'.format(price))
            amountGiven = amountGiven - price
            break