How to use the nlu.NaturalLanguageUnderstander function in nlu

def main():
    logger = logging.getLogger()

    confidence_threshold = .5
    nlu = NaturalLanguageUnderstander(confidence_threshold, logger)

    # Register the NLU messages we want
    nlu.register_message(YesNoMessage)
    nlu.register_message(SearchMessage)
    nlu.register_message(SystemMessage)

    fil = open('INGREDIENTS.txt', 'r')

    # Skip comments and empty lines
    input_messages = (l.strip() for l in fil if not re.search('^\s*($|#)', l))
    for line in islice(input_messages, 0, LIMIT):
        messages = nlu.parse_input(line)
        print line
        for message in messages:
            print message.__class__
            print pprint.pformat(message.frame)

Create a new instance of the chatbot application.

        >>> from database import Database
        >>> db = Database('sqlite:///:memory:')
        >>> bot = Chatbot(db, logging.getLogger())
        >>> response = bot.handle_input("Hi!")
        """
        self.prompt = '-> '
        self.creative_mode = False          # enables creative mode, temporarilly.
                                            # creative mode allows concurrent activity
                                            # between creative subgroup and lev1, lev2
        self.enable_debug = enable_debug
        self.db = db
        self.log = logger
        self.nlg = NaturalLanguageGenerator(logger.getChild('nlg'))
        self.nlu = NaturalLanguageUnderstander(0.5, logger.getChild('nlu'))
        self.dm = DialogueManager(db, logger.getChild('dm'))
        #
        self.creative_nlp = CreativeManager(db, logger.getChild('creative'), self.nlu, self.nlg, self.dm)
        #
        self.log.debug("Chatbot instantiated")
        self.last_bot_output = ""

        # Register the NLU messages we want
        self.nlu.register_message(YesNoMessage)
        self.nlu.register_message(SearchMessage)
        self.nlu.register_message(SystemMessage)
        startup(self.nlg)