我的代码现在处于无限循环中，显示甜甜圈的菜单选项。我想要它，以便用户选择所需数量的甜甜圈，直到输入“ 5”。
这是我的代码：
print("Welcome to Dino's International Doughnut Shoppe!")
name = input("Please enter your name to begin: ")
#doughnuts menu
loop = 0
while loop == 0:
choice = 0
while choice not in [1,2,3,4]:
print("Please enter a valid choice from 1-4.")
print("Please select a doughnut from the following menu: ")
print("1. Chocolate-dipped Maple Puff ($3.50 each)")
print("2. Strawberry Twizzler ($2.25 each)")
print("3. Vanilla Chai Strudel ($4.05 each)")
print("4. Honey-drizzled Lemon Dutchie ($1.99)")
print("5. No more doughnuts.")
choice = int(input(">"))
if choice == 1:
chocolate = int(input("How many chocolate-dipped Maple Puff(s) would you like to purchase? "))
elif choice == 2:
strawberry = int(input("How many Strawberry Twizzler(s) would you like to purchase? "))
elif choice == 3:
vanilla = int(input("How many Vanilla Chai Strudel(s) would you like to purchase? "))
elif choice == 4:
honey = int(input("How many Honey-drizzled Lemon Dutchie(s) would you like to purchase? "))
elif choice == 5:
print(f"{name}, Here is your receipt: ")
if choice == 1:
print("==========================================")
print(f"{chocolate} Chocolate Dipped Maple Puffs")
print("==========================================")
print(f"Total Cost: ${chocolate*3.50:.2f}")
elif choice == 2:
print("==========================================")
print(f"{strawberry} Strawberry Twizzlers")
print("==========================================")
print(f"Total Cost: ${strawberry*2.25:.2f}")
elif choice == 3:
print("==========================================")
print(f"{vanilla} Vanilla Chai Strudels")
print("==========================================")
print(f"Total Cost: ${vanilla*4.05:.2f}")
elif choice == 4:
print("==========================================")
print(f"{honey} Honey-drizzled Lemon Dutchies")
print("==========================================")
print(f"Total Cost: ${honey*1.99:.2f}")
print("Thank you for shopping at Dino's International Doughnut Shoppe! Please come again!")
所以现在代码只连续显示甜甜圈菜单，但是我想要这样，所以当输入5时，它将转到数学计算/代码结尾。
答案 0 :(得分：2)
这里有一些问题。
首先，响应选择的逻辑不在您的while循环之外。可以通过缩进整个块来解决。
第二次，当用户输入5时，while choice not in [1,2,3,4]:中的条件评估为True，因此提示用户再次输入有效选项。可以通过完全删除内部while循环来解决此问题。
最后，到达elif choice == 5块时，用户将看不到这些收据打印内容，因为choice是5，因此不是1，2 ，3或4。我认为您的意思是chocolate，strawberry，vanilla或honey的计数为非零。而且这些都应该是if而不是elif块，因为它们彼此独立（用户可以获得一些巧克力和一些香草）。
请记住，这里是一个重构：
print("Welcome to Dino's International Doughnut Shoppe!")
name = input("Please enter your name to begin: ")
#doughnuts menu
chocolate = strawberry = vanilla = honey = 0
done = False
while not done:
print("Please enter a valid choice from 1-4.")
print("Please select a doughnut from the following menu: ")
print("1. Chocolate-dipped Maple Puff ($3.50 each)")
print("2. Strawberry Twizzler ($2.25 each)")
print("3. Vanilla Chai Strudel ($4.05 each)")
print("4. Honey-drizzled Lemon Dutchie ($1.99)")
print("5. No more doughnuts.")
choice = int(input(">"))
if choice == 1:
chocolate = int(input("How many chocolate-dipped Maple Puff(s) would you like to purchase? "))
elif choice == 2:
strawberry = int(input("How many Strawberry Twizzler(s) would you like to purchase? "))
elif choice == 3:
vanilla = int(input("How many Vanilla Chai Strudel(s) would you like to purchase? "))
elif choice == 4:
honey = int(input("How many Honey-drizzled Lemon Dutchie(s) would you like to purchase? "))
elif choice == 5:
done = True
print(f"{name}, Here is your receipt: ")
if chocolate > 1:
print("==========================================")
print(f"{chocolate} Chocolate Dipped Maple Puffs")
print("==========================================")
print(f"Total Cost: ${chocolate*3.50:.2f}")
if strawberry > 1:
print("==========================================")
print(f"{strawberry} Strawberry Twizzlers")
print("==========================================")
print(f"Total Cost: ${strawberry*2.25:.2f}")
if vanilla > 1:
print("==========================================")
print(f"{vanilla} Vanilla Chai Strudels")
print("==========================================")
print(f"Total Cost: ${vanilla*4.05:.2f}")
if honey > 1:
print("==========================================")
print(f"{honey} Honey-drizzled Lemon Dutchies")
print("==========================================")
print(f"Total Cost: ${honey*1.99:.2f}")
print("Thank you for shopping at Dino's International Doughnut Shoppe! Please come again!")
答案 1 :(得分：0)
tl; dr 检查答案底部的改进版本
您可以使用second form of iter方便地循环用户输入，直到给出特定值为止，在这种情况下为def get_choice():
while True:
choice = input('> ')
if choice in ('1', '2', '3', '4', '5'):
return int(choice)
else:
print("Please enter a valid choice from 1-5.")
if __name__ == '__main__':
print("Please select doughnuts from the following menu: ")
print("1. Chocolate-dipped Maple Puff ($3.50 each)")
print("2. Strawberry Twizzler ($2.25 each)")
print("3. Vanilla Chai Strudel ($4.05 each)")
print("4. Honey-drizzled Lemon Dutchie ($1.99)")
print("5. No more doughnuts.")
order = set(iter(get_choice, 5))
print(order)
。
Please select doughnuts from the following menu:
1. Chocolate-dipped Maple Puff ($3.50 each)
2. Strawberry Twizzler ($2.25 each)
3. Vanilla Chai Strudel ($4.05 each)
4. Honey-drizzled Lemon Dutchie ($1.99)
5. No more doughnuts.
> 2
> 4
> 3
> 7
Please enter a valid choice from 1-5.
> 5
{2, 3, 4}
set如您所见，这生成了 doughnuts = [
{'name': 'Chocolate-dipped Maple Puff', 'price': 3.50},
{'name': 'Stawberry Twizzler', 'price': 2.25},
...
]
个订单，这些订单可用于请求其他输入。
尽管，在这里使用一堆elif语句并不是最佳选择，因为它会增加很多重复并且不是很容易维护。相反，您应该使用词典列表来存储每个甜甜圈的特定信息。
print现在，上面的所有 for i, doughnut in enumerate(doughnuts, start=1):
print(f'{i}. {doughnut["name"]} (${doughnut["price"]} each)')
print(f'{i + 1}. No more doughnuts.')
都可以像这样简化。
list对于算术，您应该做同样的事情，当变量高度相关时，它们的值应该一起存储在dict或receipt = [
{
**doughnuts[i],
'qty': int(input(f'How many {doughnuts[i]["name"]} '))
}
for i in order
]
print(f"Here is your receipt: ")
for item in receipt:
print("==========================================")
print(f"{item['qty']} {item['name']}")
print("==========================================")
print(f"Total Cost: ${item['qty'] * item['price']:.2f}")
中。
1. Chocolate-dipped Maple Puff ($3.5 each)
2. Stawberry Twizzler ($2.25 each)
3. Vanilla Chai Strudel ($4.05 each)
4. Honey-drizzled Lemon Dutchie ($1.99 each)
5. No more doughnuts.
> 1
> 2
> 5
How many Stawberry Twizzler 2
How many Vanilla Chai Strudel 1
Here is your receipt:
==========================================
2 Stawberry Twizzler
==========================================
Total Cost: $4.50
==========================================
1 Vanilla Chai Strudel
==========================================
Total Cost: $4.05
doughnuts然后，您得到了代码的简化版本。更短，更容易维护：要添加甜甜圈，您只需要更新初始列表doughnuts = [
{'name': 'Chocolate-dipped Maple Puff', 'price': 3.50},
{'name': 'Stawberry Twizzler', 'price': 2.25},
{'name': 'Vanilla Chai Strudel', 'price': 4.05},
{'name': 'Honey-drizzled Lemon Dutchie', 'price': 1.99}
]
def get_choice():
allowed = map(str, range(1, len(doughnuts) + 2))
while True:
choice = input('> ')
if choice in allowed:
return int(choice)
else:
print("Please enter a valid choice.")
if __name__ == '__main__':
for i, doughnut in enumerate(doughnuts, start=1):
print(f'{i}. {doughnut["name"]} (${doughnut["price"]} each)')
print(f'{i + 1}. No more doughnuts.')
receipt = [
{
**doughnuts[i],
'qty': int(input(f'How many {doughnuts[i]["name"]}'))
}
for i in set(iter(get_choice, 5))
]
print(f"Here is your receipt: ")
for item in receipt:
print("==========================================")
print(f"{item['qty']} {item['name']}")
print("==========================================")
print(f"Total Cost: ${item['qty'] * item['price']:.2f}")
。
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