movie_review_tag.py

import random
import nltk
from nltk.corpus import movie_reviews
documents = [(list(movie_reviews.words(fileid)), category) for category in movie_reviews.categories() for fileid in movie_reviews.fileids(category)]
random.shuffle(documents)


all_words = nltk.FreqDist(w.lower() for w in movie_reviews.words())
word_features = list(all_words)[:2000]

def document_features(document):
    document_words = set(document)
    features = {}
    for word in word_features:
        features['contains({})'.format(word)] = (word in document_words)
    return features

#cargar data y poner en el formato que acepta el clasificador ([caracteristicas],'tag')
featuresets = [(document_features(d), c) for (d,c) in documents]

train_set, test_set = featuresets[100:], featuresets[:100]
classifier = nltk.NaiveBayesClassifier.train(train_set)

print(nltk.classify.accuracy(classifier, test_set))
print(classifier.show_most_informative_features(5))