# Check that users have entered a valid
# option based on a list
ans = ""

def string_checker(user_response, valid_ans):

    user_response = user_response.lower()

    if user_response in valid_ans:
        return True

    return False


while True:
    ans = input("morb?")
    tf = string_checker(ans, ["yes","no"])
    if tf:
        print(f"you picked {ans}")
        break
    else:
        continue