def string_check(question, valid_ans_list, num_letters):
    """Check that users enter a 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_ans_list:
            if response == item:
                return item

            elif response == item[:num_letters]:
                return item
        print(f"Please choose an option from the list {valid_ans_list}")

while True:
    bye = ["continue", "exit"]
    leave = string_check("Exit or continue?  ", bye, 1)
    # Exit loop

    if leave == "continue":
        continue
    elif leave == "exit":

        break