LPTHW Exercise 48

lexicon.py

class LexiconC(object):
    def __init__(self):
        #constants
        # TODO: Can we make these as constants so they can be accessed from out side the class with just the class name ?
        self.C_DIRECTION_WORDS = "direction"
        self.C_VERBS = "verb"
        self.C_STOP_WORDS = "stop"
        self.C_NOUNS = "noun"
        self.C_NUMBER = "number"
        self.C_ERROR = "error"

        #lexicon
        self.direction_words = ['north', 'south', 'east', 'west', 'down', 'up', 'left', 'right', 'back']
        self.verbs = ['go', 'stop', 'kill', 'eat']
        self.stop_words = ['the', 'in', 'of', 'from', 'at', 'it']
        self.nouns = ['door', 'bear', 'princess', 'cabinet']

    def get_tuple(self, word):
        ret_val = None
        lword = word.lower()
        if(lword in self.direction_words):
            ret_val = (self.C_DIRECTION_WORDS, word)
        elif(lword in self.verbs):
            ret_val = (self.C_VERBS, word)
        elif(lword in self.stop_words):
            ret_val = (self.C_STOP_WORDS, word)
        elif(lword in self.nouns):
            ret_val = (self.C_NOUNS, word)
        elif(self.convert_number(lword) != None):
            ret_val = (self.C_NUMBER, self.convert_number(lword))
        else:
            ret_val = (self.C_ERROR, word)


    def convert_number(self, text):
        try:
            return int(text)
        except ValueError:
            return None


def scan(line):
    print "Scanning line '%s'" % line
    the_lexicon = LexiconC()
    ret_val = []
    words = line.split()
    for word in words:
        the_tuple = the_lexicon.get_tuple(word)
        ret_val.append(the_tuple)

    return ret_val

lexicon_tests.py

from nose.tools import *
from ex48 import lexicon

def setup():
    print "SETUP!"

def teardown():
    print "TEAR DOWN!"

def test_directions():
    assert_equal(lexicon.scan("north"), [('direction', 'north')])
    result = lexicon.scan("north south east")
    assert_equal(result, [('direction', 'north'),
                          ('direction', 'south'),
                          ('direction', 'east')])

def test_verbs():
    assert_equal(lexicon.scan("go"), [('verb', 'go')])
    result = lexicon.scan("go kill eat")
    assert_equal(result, [('verb', 'go'),
                           ('verb', 'kill'),
                           ('verb', 'eat')])

def test_stops():
    assert_equal(lexicon.scan("the"), [('stop', 'the')])
    result = lexicon.scan("the in of")
    assert_equals(result, [('stop', 'the'),
                           ('stop', 'in'),
                           ('stop', 'of')])

def test_nouns():
    assert_equal(lexicon.scan("bear"), [('noun', 'bear')])
    result = lexicon.scan("bear princess")
    assert_equal(result, [('noun', 'bear'),
                                                                                                                                                     
def test_numbers():
    assert_equal(lexicon.scan("1234"), [('number', 1234)])
    result = lexicon.scan("3 91234")
    assert_equal(result, [('number', 3),
                          ('number', 91234)])

def test_errors():
    assert_equal(lexicon.scan("ASDFADFA"), [('error', "ASDFADFA")])
    result = lexicon.scan("bear IAS princess")
    assert_equal(result, [('noun', 'bear'),
                          ('error', 'IAS'),
                          ('noun', 'princess')])