如何让程序不断检查 while 语句条件？

Question

我正在为一个简单的食物菜单类型的东西制作这个代码，并希望将用户限制在 6 个项目。 我正在使用小于或等于 6 的 while 语句，但即使 orderitems > 6 它也会继续运行。如果 orderitems > 6，我如何让 python 停止 while 语句？

foodorders = []
drinkorders = []
orderitems=0
while orderitems <= 6:
    print("SANDWHICH MENU")
    print("BLT.......... 5.99")
    print("FRENCH DIP .......... 7.99")
    print("TURKEY CLUB .......... 4.99")
    print("TRUFFLE .......... 11.99")
    print("GRILLED CHEESE.......... 3.99")
    moresand="yes"
    while moresand=="yes":
        print("Which sandwhich do you want?")
        sand=str(input())
        foodorders.append(sand)
        orderitems=orderitems+1
        print("Would you like another sandwhich?")
        moresand=str(input())
    else:
        print("SOUP MENU")
        print("FRENCH ONION .......... 5.99")
        print("BROCCOLI .......... 3.99")
        print("CLAM CHOWDER .......... 4.99")
        print("SPLIT PEA .......... 3.99")
        print("CHCIKEN NOODLE .......... 2.99")
        moresoup="yes"
        while moresoup=="yes":
            print("Which soup do you want?")
            soup=str(input())
            foodorders.append(soup)
            orderitems=orderitems+1
            print("Would you like another soup?")
            moresoup=str(input())
        else:
            print("DRINK MENU")
            print("SMALL .......... 1.99")
            print("MEDIUM .......... 2.99")
            print("LARGE .......... 3.99")
            moresoda="yes"
            while moresoda=="yes":
                print("Which soda do you want?")
                soda=str(input())
                drinkorders.append(soda)
                orderitems=orderitems+1
                print("Would you like another soda?")
                moresoda=str(input())
            else:
                print("Thank you for shopping!")
    print("Your food orders are:")
    for foodorder in foodorders:
        print("A",foodorder)
    print("Your drink orders are:")
    for drinkorder in drinkorders:
        print("A",drinkorder,"Soda")

else:
    print("Looks like that's all of our stock, sorry about that! Have a great rest of your day!")
    print("Your final food orders are:")
    for foodorder in foodorders:
        print("A",foodorder)
    print("Your drink orders are:")
    for drinkorder in drinkorders:
        print("A",drinkorder,"Soda")

Answer 1

不，你不能有一个程序来不断检查 while 语句。 每个循环只会检查一次。
您可以使用 if 语句重新检查 while 循环中的条件。
您可以使用 break 来停止 while 循环：

foodorders = []
drinkorders = []
orderitems=0
while orderitems < 7:  # [1, 2, 3, 4, 5, 6]  -> 6 orders
    print("SANDWHICH MENU")
    print("BLT.......... 5.99")
    print("FRENCH DIP .......... 7.99")
    print("TURKEY CLUB .......... 4.99")
    print("TRUFFLE .......... 11.99")
    print("GRILLED CHEESE.......... 3.99")
    moresand="yes"
    while moresand=="yes":
        print("Which sandwhich do you want?")
        sand=str(input())
        foodorders.append(sand)
        orderitems=orderitems+1
        if orderitems >= 6: break
        print("Would you like another sandwhich?")
        moresand=str(input())
    else:
        print("SOUP MENU")
        print("FRENCH ONION .......... 5.99")
        print("BROCCOLI .......... 3.99")
        print("CLAM CHOWDER .......... 4.99")
        print("SPLIT PEA .......... 3.99")
        print("CHCIKEN NOODLE .......... 2.99")
        moresoup="yes"
        while moresoup=="yes":
            print("Which soup do you want?")
            soup=str(input())
            foodorders.append(soup)
            orderitems=orderitems+1
            if orderitems >= 6: break
            print("Would you like another soup?")
            moresoup=str(input())
        else:
            print("DRINK MENU")
            print("SMALL .......... 1.99")
            print("MEDIUM .......... 2.99")
            print("LARGE .......... 3.99")
            moresoda="yes"
            while moresoda=="yes":
                print("Which soda do you want?")
                soda=str(input())
                drinkorders.append(soda)
                orderitems=orderitems+1
                if orderitems >= 6: break
                print("Would you like another soda?")
                moresoda=str(input())
            else:
                print("Thank you for shopping!")
    print("Your food orders are:")
    for foodorder in foodorders:
        print("A",foodorder)
    print("Your drink orders are:")
    for drinkorder in drinkorders:
        print("A",drinkorder,"Soda")

else:
    print("Looks like that's all of our stock, sorry about that! Have a great rest of your day!")
    print("Your final food orders are:")
    for foodorder in foodorders:
        print("A",foodorder)

Answer 2

要做的简单事情是更改while moresand=="yes":更改为while moresand=="yes" and orderitems <= 5:对 moreSoup 和 moreSoda 执行相同操作。