Implement program to accept only certain coins

Question

I've nearly finished my program but have to add a feature so it only accepts certain coins and will throw a message if a wrong coin is inserted.

any help would be appreciated

def main():
    total = 0
    coins = [10, 20, 30]
    while True:
        total += int(input("Insert one coin at a time: ").replace('"', '').replace("'", '').strip())
        coke = 50
        print(total)
        if total > coke:
            print("Change Owed =", total - coke)
            return
        elif total == coke:
            print("No Change Owed, Here's a coke ")
            return
        else:
            print("Amount Due =", coke-total)


main()

Answer 1

As suggested by @Barmar, create a list of allowed coins and make sure the input falls in the list:

def main():
    total = 0
    allowed_coins = [25,50,100]
    coke = 50
    while True:
        coin_input = int(input("Insert one coin at a time: ").replace('"', '').replace("'", '').strip())
        if coin_input not in allowed_coins:
            print("Invalid Coin Amount Due =", coke - total)
            return
        total = total + coin_input
        if total > coke:
            print("Change Owed =", total - coke)
            return
        elif total == coke:
            print("No Change Owed, Here's a coke ")
            return
        else:
            print("Amount Due =", coke-total)
main()

Answer 2

You need to check the coin before adding it to total . If it's not valid, skip the rest of the loop and ask again

def main():
    total = 0
    coins = [10, 20, 30]
    while True:
        coin = int(input("Insert one coin at a time: ").replace('"', '').replace("'", '').strip())
        if coin not in coins:
            print("That's not an allowed coin, try again")
            continue
        total += coin
        coke = 50
        print(total)
        if total > coke:
            print("Change Owed =", total - coke)
            return
        elif total == coke:
            print("No Change Owed, Here's a coke ")
            return
        else:
            print("Amount Due =", coke-total)

main()