# Check that users have entered a valid answer
# option based on list

def string_checker(question, valid_ans):

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

    while True:

        # Get user response and make sure it's lowercase
        user_response = input(question).lower()

        for item in valid_ans:
            # check if the user response is a word in the list
            if item == user_response:
                return item

            # check if the user response is the same as
            # the first letter of an item in the list
            elif user_response == item[0]:
                return item

        # print error if user does not entre something that is valid
        print(error)
        print()


# Main routine goes here
yes_no = ["yes", "no"]
# ask user if they want to see the instructions and display
# them if requested
want_instructions = string_checker("Do you want to see the instructions? ", yes_no)

print(f"You chose, {want_instructions}")