def num_check(question, num_type, exit_code=None):
    """Checks users enter an integer / float that is more than
    zero (or the optional exit code)"""

    if num_type == "integer":
        error = "Oops - please enter an integer more than zero."
        change_to = int
    else:
        error = "Oops - please enter a number more than zero."
        change_to = float

    while True:
        response = input(question).lower()

        # check for the exit code
        if response == "xxx":
            return response

        try:
            # Change the response to an integer amd check that it's more than zero
            response = change_to(response)

            if response > 0:
                return response
            else:
                print(error)

        except ValueError:
            print(error)

def not_blank(question):
    """Checks that a user response is not blank"""

    while True:
        response = input(question)

        if response != "":
            return response

        print("Sorry, this can't be blank. Please try again. \n")