Python萌新求助怎么将input输入的内容限制在字典的键值之中？

怎么将input输入的内容限制在字典的键值之中？

def carculate(money,price):

    result = int(money)-int(price)

    if int(result)>0:

        print(f"Send back you {int(result)}")

    elif int(result)==0:

        print(f"Thankyou for shopping!")

    elif int(result)<0:

        left_money=0-int(result)

        print(f"Sorry,you need {left_money} more to pay!")

active = True

while active:

    prices={"cake1":12,'cake2':24,'cola1':56,'cola2':78,'candy1':34,'candy2':57}

    price=prices[input(f"Chose your goods:\n").lower()]

    money=input("Give the money:\n")

    carculate(money,price)

    asking=input(f"Have you finihed? anser'yes'or'not'.\n")

    if asking.lower() == 'yes':

        print(f"See you next time!")

        break

    else:

        print(f"All depends on you.")

        continue

在 price=prices[input(f"Chose your goods:\n").lower()]一行，成功把输入内容限制在字典prices的键之内，但是输入字典没有的内容会直接报错报错，如何更改使得如果用户输入不属于字典键的内容时进行提示而不是直接报错？

顶顶顶，求看论坛大佬们的实力

不用[]改成.get()，判断一下，为空则print提示

cake=input(f"Chose your goods:\n").lower()
if cake not in prices.keys:
    print('Choice again')
    pass
else:
    price=prices[cake]
    ..............

def calculate(money, price):
    result = int(money) - int(price)
    if int(result) > 0:
        print(f"Send back you {int(result)}")
    elif int(result) == 0:
        print(f"Thank you for shopping!")
    elif int(result) < 0:
        left_money = 0 - int(result)
        print(f"Sorry, you need {left_money} more to pay!")


active = True
prices = {"cake1": 12, "cake2": 24, "cola1": 56, "cola2": 78, "candy1": 34, "candy2": 57}

while active:
    chosen_item = ""
    while chosen_item not in prices:  # 输入内容限制在prices的键之内
        chosen_item = input("Choose your goods:\n").lower()
        if chosen_item not in prices:
            print("Invalid item. Please choose again.")
    price = prices[chosen_item]
    money = input("Give the money:\n")
    calculate(money, price)
    asking = input("Have you finished? Answer 'yes' or 'no'.\n")
    if asking.lower() == "yes":
        print("See you next time!")
        break
    else:
        print("All depends on you.")
        continue