cluster_example.py

import sys

import numpy
from nltk.cluster import KMeansClusterer, GAAClusterer, euclidean_distance
import nltk.corpus
from nltk import decorators
import nltk.stem

stemmer_func = nltk.stem.snowball.EnglishStemmer().stem
stopwords = set(nltk.corpus.stopwords.words('english'))

@decorators.memoize
def normalize_word(word):
    return stemmer_func(word.lower())

def get_words(titles):
    words = set()
    for title in job_titles:
        for word in title.split():
            words.add(normalize_word(word))
    return list(words)

@decorators.memoize
def vectorspaced(title):
    title_components = [normalize_word(word) for word in title.split()]
    return numpy.array([
        word in title_components and not word in stopwords
        for word in words], numpy.short)

if __name__ == '__main__':

    filename = 'example.txt'
    if len(sys.argv) == 2:
        filename = sys.argv[1]

    with open(filename) as title_file:

        job_titles = [line.strip() for line in title_file.readlines()]

        words = get_words(job_titles)

        # cluster = KMeansClusterer(5, euclidean_distance)
        cluster = GAAClusterer(5)
        cluster.cluster([vectorspaced(title) for title in job_titles if title])

        # NOTE: This is inefficient, cluster.classify should really just be
        # called when you are classifying previously unseen examples!
        classified_examples = [
                cluster.classify(vectorspaced(title)) for title in job_titles
            ]

        for cluster_id, title in sorted(zip(classified_examples, job_titles)):
            print cluster_id, title

example.txt

Not so skilled worker
Skilled worker
Banana picker
Police officer
Office worker
Fireman
IT consultant
Rapist of old ladies
Engineer
Stupid bastard son
Genious computer analyst
Computer banana peeler
Potato peeler
CEO of a major business
Business economist
Data analyst
Economist analyst bastard
Psychologist data enumerator
Psychologist genious
Evil genious
Murderer and rapist of cats
Cat psychologist
Top Software Engineer in IT with NLTK experience
xim
fission6