# 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 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 a word in the list
            # the first letter of an item in the list
            elif user_response == item[0]:
                return item

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


# Main routine

# testing loop ...
while True:
    want_instructions = yes_no("Do you want to see the instructions? ")
    print(f"you chose {want_instructions}")

print("we done")