我在这里找到了一小段代码:
import nltk.classify.util
from nltk.classify import NaiveBayesClassifier
from nltk.corpus import movie_reviews
from nltk.corpus import stopwords
def word_feats(words):
return dict([(word, True) for word in words])
negids = movie_reviews.fileids('neg')
posids = movie_reviews.fileids('pos')
negfeats = [(word_feats(movie_reviews.words(fileids=[f])), 'neg') for f in negids]
posfeats = [(word_feats(movie_reviews.words(fileids=[f])), 'pos') for f in posids]
negcutoff = len(negfeats)*3/4
poscutoff = len(posfeats)*3/4
trainfeats = negfeats[:negcutoff] + posfeats[:poscutoff]
testfeats = negfeats[negcutoff:] + posfeats[poscutoff:]
print 'train on %d instances, test on %d instances' % (len(trainfeats), len(testfeats))
classifier = NaiveBayesClassifier.train(trainfeats)
print 'accuracy:', nltk.classify.util.accuracy(classifier, testfeats)
classifier.show_most_informative_features()
但是我如何对可能在语料库中的随机词进行分类。
classifier.classify('magnificent')
不工作。它需要某种对象吗?
非常感谢你。
编辑:感谢@unutbu 的反馈和一些在这里挖掘并阅读原始帖子的评论,以下产生此代码的“pos”或“neg”(这是一个“pos”)
print(classifier.classify(word_feats(['magnificent'])))
这会产生对“pos”或“neg”这个词的评估
print(classifier.prob_classify(word_feats(['magnificent'])).prob('neg'))