在python的while循环中使用if语句？

Question

我有一个自动售货机的问题，用户有3个选择：

1. 水2。可乐3。佳得乐

   水=1.00美元，可乐=1.50美元，佳得乐=2.00美元

在从用户那里输入了25美分、10美分、5美分和5美分之后，我用美元计算了总数。现在我要检查三种饮料的总量是否足够。如果金额小于成本，我需要提示用户再试一次，如果金额大于，那么我需要显示一条消息，显示用户的更改金额。我相信这需要while循环和if，elif，else语句。以下是我目前的计划：

import sys 
print('You have three drinks to choose from this Vending Machine: \n 1. Water \n 2. Cola \n 3. Gatorade')
water = 1.00
cola = 1.50
gatorade = 2.00
choice = 0
while not choice:
  try:
    choice = int(input('Please select any one of the three choices of drinks (1,2 or 3) from the list above'))
    if choice not in (1,2,3):
        raise ValueError
  except ValueError:
    choice = 0
    print("That is not a valid choice ! Try again")
if choice == 1:
   print("1. water = $1.00")
elif choice == 2:
   print("2. cola = $1.50")
elif choice == 3:
   print("3. gatorade = $2.00")

qrt = int(input("How many quarters did you insert ?"))
dm = int(input("How many dimes did you insert ?"))
nk = int(input("How many nickels did you insert ?"))
pn = int(input("How many pennies did you insert ?"))

total = qrt/4 + dm/10 + nk/20 + pn/100

现在，我需要检查总量（用户插入的）是否大于或小于他选择的饮料的成本。你知道吗

如果更大，我需要返回更改（显示更改金额的消息）。你知道吗

如果较小，那么我需要提示用户再次尝试插入硬币。你知道吗

我该怎么做？你知道吗

Answer 1

我想这就是你需要做的。也可以根据您的需求使用逻辑并修改代码。你知道吗

别照搬。希望有帮助。你知道吗

import sys 
print('You have three drinks to choose from this Vending Machine: \n 1. Water \n 2. Cola \n 3. Gatorade')
water = 1.00
cola = 1.50
gatorade = 2.00
choice = 0
while not choice:
    try:
        choice = int(input('Please select any one of the three choices of drinks (1,2 or 3) from the list above: '))
        if choice not in (1,2,3):
            raise ValueError
    except ValueError:
        choice = 0
        print("That is not a valid choice ! Try again")

if choice == 1:
    print("1. water = $1.00")
    total_to_be = 1.00
elif choice == 2:
    print("2. cola = $1.50")
    total_to_be = 1.50
elif choice == 3:
    print("3. gatorade = $2.00")
    total_to_be = 2.00

qrt = int(input("How many quarters did you insert ?"))
dm = int(input("How many dimes did you insert ?"))
nk = int(input("How many nickels did you insert ?"))
pn = int(input("How many pennies did you insert ?"))

total = qrt/4 + dm/10 + nk/20 + pn/100

# total = round(total, 2)

while total != total_to_be: 

    if total >= total_to_be:
        print(total)
        break

    else:
        print("======================= Please try Again ================================")
        qrt = int(input("How many quarters did you insert ?"))
        dm = int(input("How many dimes did you insert ?"))
        nk = int(input("How many nickels did you insert ?"))
        pn = int(input("How many pennies did you insert ?"))

        total = qrt/4 + dm/10 + nk/20 + pn/100