lexicon.py

def convert_numbers(s):
	try:
		return int(s)
	except ValueError:
		return None

def scan(sentence):
	words = sentence.split()
	sentence = []
	for word in words:
		word_tuple = ('error', word)
		num = convert_numbers(word)
		if (num != None):
			word_tuple = ('number', num)

		lc_word = word.lower()

		if (lc_word == 'north' or lc_word == 'south' or lc_word == 'east' or lc_word == 'west' or lc_word == 'down' or lc_word == 'up' or lc_word == 'left' or lc_word == 'right' or lc_word == 'right'):
			word_tuple = ('direction', word)

		if (lc_word == 'go' or lc_word == 'stop' or lc_word == 'kill' or lc_word == 'eat'):
			word_tuple = ('verb', word)

		if (lc_word == 'the' or lc_word == 'in' or lc_word == 'of' or lc_word == 'from' or lc_word == 'at' or lc_word == 'it'):
			word_tuple = ('stop', word)

		if (lc_word == 'door' or lc_word == 'bear' or lc_word == 'princess' or lc_word == 'cabinet'):
			word_tuple = ('noun', word)

		sentence.append(word_tuple)

	return sentence