# Check that users have entered a valid
# option based on a list
def string_checker(question, valid_ans=('yes', 'no')):

    error = f"please enter a valid option from following list: {valid_ans}"

    while True:

        user_response = input(question).lower()

        for item in valid_ans:
            if item == user_response:
                return item

            elif user_response == item[0]:
                return item
        # print error if user does not enter something that valid
        print(error)
        print()


rps_list = ["rock", "paper", "scissors", "xxx"]

want_instructions = string_checker( "Do you want to see instructions?")

print("you choose: ", want_instructions)

user_choice = string_checker( "choose: ", rps_list)
print("You choose: ", user_choice)