# Functions go here
# noinspection PyUnreachableCode
def string_check(question, valid_list=('yes', 'no'),
                 num_letters=1):
    """Checks that users enter the full word
    or the 'n' letter/s of a word from a list of valid responses"""

    while True:

        response = input(question).lower()

        for item in valid_list:

            # check if the response is the entire word
            if response == item:
                return item



            # check if it's the 'n' letters
            elif response == item[:num_letters]:
                return item

        print(f"Please choose an option from {valid_list}")


# Main routine goes here


    like_pizza = string_check("Would you like some pizza?", ['yes', 'no'])
    print(f"You chose: {like_pizza}")