How do I use a while loop for 2 strings in python?

Question

I am trying to make a program that asks you for a currency that is stated. And I want to make a while loop that repeats enter a currency until a correct currency is inputed. However when I hit run it says error right where i entered the while loop

    #current currency == num1
    num1 = str(input("Exchangeable currencies: usd, eur, cad, inr, jpy, vnd, krw, btc. Enter 
    current currency"))

    #target currency == num2
    num2 = str(input("Enter target currency"))
    num1amount = int(input("Enter amount of money"))

    list ["usd", "eur", "cad", "inr", "jpy", "vnd", "krw", "btc"] 

    while num1 or num2 != from list:
        print "wrong currency: "
        #current currency == num1
        num1 = str(input("Exchangeable currencies: usd, eur, cad, inr, jpy, vnd, krw, btc. 
        Enter current currency"))

        #target currency == num2
        num2 = str(input("Enter target currency"))
        num1amount = int(input("Enter amount of money"))
    break

Answer 1

您的代码中有几个错误，但关于 while 循环，您可能希望执行以下操作：

while ((num1 not in list) and (num2 not in list)):