跳出 while 循環

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

我想在客戶選擇其中一個選項后打破循環

Answer 1

看來您有 boolean openMenu並且只有在openMenu = True時才進入 while 循環。

因此，解決這個問題的一種方法是在每個條件語句之后設置openMenu = False 。

你將會擁有：

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，您似乎並不真的需要 while 循環，因為您的 for 循環遍歷了 shoppingList 中的所有元素。

Answer 2

我真的不明白你的問題。 如果你想從 while 循環中中斷，當滿足特定條件時，使用'break'語句。

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