我正在努力使用这段Python代码。问题是，当用户输入错误时，我需要我的代码保持循环，直到他们输入有效的答案。 这就是代码应该如何工作：提示用户选择饮料，然后选择美食，然后选择菜肴。在此之后，程序显示用户想要的订单。
Order = [ 'No drink', 'No food' ]
Yesses = [ 'y', 'yes', 'yep', 'okay', 'sure' ]
DRINK = 0
FOOD = 1
print("Welcome to Hungary house!")
print("")
print("First, let me get your drink order, if any.")
answer = input("Would you like something to drink? ").lower()
if answer in Yesses:
print("What drink would you prefer?")
print ("1: Fanta")
print ("2: Coke")
print ("3: Pepsi")
print ("4: Sprite")
choice = input("Please enter a drink from the menu above\n").lower()
if choice == "1" or choice == "fanta":
Order[DRINK] = "Fanta"
if choice == "2" or choice == "coke":
Order[DRINK] = "Coke"
if choice == "3" or choice == "pepsi":
Order[DRINK] = "Pepsi"
if choice == "4" or choice == "sprite":
Order[DRINK] = "Sprite"
print ("You have chosen: " + Order[DRINK])
print("")
print("Now, let me get your food order, if any.")
answer = input("Do you want any food (Y/N)? ").lower()
if answer in Yesses:
answer = input("Do you want Italian,Indian or Chinese food?\n").lower()
if answer == "indian":
answer = input("Do you want Curry or Onion Bhaji?\n").lower()
if answer == "curry":
Order[FOOD] = "Curry"
answer = input("With your curry, do you want Rice or Naan?\n").lower()
if answer == "rice":
Order.append("- with rice")
if answer == "naan":
Order.append("- with naan")
if answer == "onion bhaji" or answer == "bhaji":
Order[FOOD] = "Onion Bhaji"
answer = input("With your bhaji, do you want Chili or Peppers?\n").lower()
if answer == "chili":
Order.append("- with chili")
if answer == "peppers":
Order.append("- with peppers")
if answer == "chinese":
answer = input("Do you want Chicken Wings or Noodles?\n").lower()
if answer == "chicken wings" or answer == "wings":
Order[FOOD] = "Chicken Wings"
answer = input("With your wings, do you want Chips or Red Peppers?\n").lower()
if answer == "chips":
Order.append("- with Chips")
if answer == "red peppers" or answer == "peppers":
Order.append("- with Red Peppers")
if answer == "noodles":
Order[FOOD] = "Noodles"
answer = input("With your noodles, do you want Meatballs or Chicken?\n").lower()
if answer == "meatballs":
Order.append("- with meatballs")
if answer == "chicken":
Order.append("- with chicken")
if answer == "italian":
answer = input("Do you want Pasta or Noodles?\n").lower()
if answer == "pasta" or answer == "Pasta":
Order[FOOD] = "Pasta"
answer = input("With your Pasta, do you want Vegetarian Toppings or meat toppings?\n").lower()
if answer == "vegetarian Toppings":
Order.append("- with Vegetarian Toppings")
if answer == "meat toppings" or answer == "meat":
Order.append("- with Meat toppings")
if answer == "pizza":
Order[FOOD] = Pizza
answer = input("With your Pizza, do you want Grilled chicken or Chicken?\n").lower()
if answer == "Grilled chicken":
Order.append("- Grilled chicken")
if answer == "seasonal vegetables":
Order.append("- seasonal vegetables")
try:
if Order[2]:
print("You have ordered the following. Your order number is 294")
print("")
print(" ", Order[DRINK])
print(" ", Order[FOOD])
except:
pass
try:
if Order[2]:
print(" ", Order[2])
except:
print("")
print("No food or drink?! Get out!")
try:
if Order[2]:
print("""
Your order should arrive within 10-50 minutes. If you wish to cancel,
please contact us at 077 3475 8675309. Thank you for your patronage!
""")
except:
pass
答案 0 :(得分：0)
<强>更新
以下是代码的第一部分while (condition):
Order = [ 'No drink', 'No food' ]
Yesses = [ 'y', 'yes', 'yep', 'okay', 'sure' ]
DRINK = 0
FOOD = 1
print("Welcome to Hungary house!")
print("")
print("First, let me get your drink order, if any.")
answer = input("Would you like something to drink? ").lower()
if answer in Yesses:
print("What drink would you prefer?")
print ("1: Fanta")
print ("2: Coke")
print ("3: Pepsi")
print ("4: Sprite")
correct = False
while (!correct):
choice = input("Please enter a drink from the menu above\n").lower()
if (choice == "1" or choice == "fanta"):
Order[DRINK] = "Fanta"
correct = True
elif (choice == "2" or choice == "coke"):
Order[DRINK] = "Coke"
correct = True
elif (choice == "3" or choice == "pepsi"):
Order[DRINK] = "Pepsi"
correct = True
elif (choice == "4" or choice == "sprite"):
Order[DRINK] = "Sprite"
correct = True
print ("You have chosen: " + Order[DRINK])
原始回答：
因此，如果它正在使用input()，您可以通过执行while循环直到该语句为真。因此，将所有代码放在循环中并在正确时满足布尔值。例如：
correct = false
while (!correct):
var = input ("your statement")
if var == "good":
correct = true
#next stuff
答案 1 :(得分：0)
使用while循环并在满意后中断：
drink = None
while drink is None:
choice = input("Please enter a drink from the menu above\n").lower()
if choice == "1" or choice == "fanta":
drink = "Fanta"
elif choice == "2" or choice == "coke":
drink = "Coke"
elif choice == "3" or choice == "pepsi":
drink = "Pepsi"
elif choice == "4" or choice == "sprite":
drink = "Sprite"
Order[DRINK] = drink
答案 2 :(得分：0)
作为一个例子，让饮料部分不断循环直到用户输入有效的东西：
while choice != "1" or choice != "2" or choice != "3" or choice != "4":
choice = input("Please enter a valid drink: ")
if choice == "1" or choice == "fanta":
Order[DRINK] = "Fanta"
if choice == "2" or choice == "coke":
Order[DRINK] = "Coke"
if choice == "3" or choice == "pepsi":
Order[DRINK] = "Pepsi"
if choice == "4" or choice == "sprite":
Order[DRINK] = "Sprite"
我认为这样可行，因为它会继续迭代循环直到满足条件。然后一旦循环完成，它将执行它下面的代码。
答案 3 :(得分：0)
while True:
choice = input("Please enter a drink from the menu above\n").lower()
if choice == "1" or choice == "fanta":
Order[DRINK] = "Fanta"
break
if choice == "2" or choice == "coke":
Order[DRINK] = "Coke"
break
if choice == "3" or choice == "pepsi":
Order[DRINK] = "Pepsi"
break
if choice == "4" or choice == "sprite":
Order[DRINK] = "Sprite"
break
这很笨重，但它最符合你已经拥有的东西。我建议将大部分这些项目移动到这样的列表中，但这对于这个答案来说有点重构。考虑下面的内容，但实际上你要做的就是将输入放入无限循环中，然后在用户正确的时候中断。
drink_list = ['fanta', 'coke', 'pepsi', 'sprite']
if choice in drink_list:
break