你如何只允许来自列表的输入？ （蟒蛇自动售货机）

Question

我需要为一台只接受某些硬币的自动售货机编码

“它将允许您输入 1p、2p、5p、10p、20p、50p 和 1.00 英镑，但它会拒绝 2.00 英镑的硬币”

我有一个列表，里面有浮点值：

coins = ["0.01","0.02","0.05","0.10","0.20","0.50","1"]

这些是硬币，我希望用户输入

coin = float(input())

在这之后我有

def balance():
     coin = float(input("Please enter your coins."))
     if coin not in coins:
            print("Incorrect coin amount! Please remember we don't accept 2 pound coins!")

     else:
        print("Correct coin amount. The coins have been added to your balance")
        fb = fb + coin

我无法让它工作，因为它只会打印“硬币数量不正确！请记住我们不接受 2 磅硬币！”。 在此之后，我已经在这里尝试了这个解决方案：Python Coding - Vending machine - How to get the user to only enter certain coins? 我认为这意味着我需要更改我的 float(input()) 并且所有内容都浮动为 int，因此将 0.01 (1p) 更改为 1。但是，当我这样做时，我仍然得到了

'int' object has no attribute 'split'

在这段代码中使用时

dict = {"KitKat":"80p", "Coca-Cola":"85p", "DairyMilk":"80p","Walkers Crisps":"90p"}
coins = ["1","2","5","10","20","50","100"]

def balance():
    inp = int(input("Please enter your coins. Please enter in pence, for example 1 pound = 100"))
    if any(int(coin) not in value for coin in inp.split()):
        print("Machine doesn't accept these coins")


else:
    print("Correct coin amount. The coins have been added to your balance")
    fb = fb + coin


def items():
    print (" 1. KitKat:" , dict['KitKat'])
    print (" 2. Coca-Cola:", dict['Coca-Cola'])
    print (" 3. Dairy Milk:", dict["DairyMilk"])
    print (" 4. Walkers Crisps:", dict["Walkers Crisps"])
snack = 1 # need a while loop, ignore
fb = 0.00
balance()
print("Your full balance is",fb)

Answer 1

我建议您将英镑转换为便士，这样您就不必进行浮点数学运算，并且只要在显示值时转换回来即可。您也可以为此使用decimal 模块，但我们暂时不要过多参与。您的最终问题似乎是您正在比较不同类型的值，以及1 != "1"。让我们先排序。

coins = [1, 2, 5, 10, 20, 50, 100]  # pence
coin_in = int(input("Enter amount (in pence): "))

if coin_in not in coins:
    # incorrect input, handle it