NLTK - 如何使用NER

Question

如何从NLTK调用NER以获取位于同一目录中的每个TXT文件的前200个字符的所有结果？

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当我尝试这段代码时:

for filename in os.listdir(ebooksFolder):
    fname, fextension = os.path.splitext(filename)
        if (fextension == '.txt'):
            newName = 'ner_' + filename
            file = open(ebooksFolder + '\\' + filename)
            rawFile = file.read()
            partToUse = rawFile[:50]
            segmentedSentences = nltk.sent_tokenize(partToUse)
            tokenizedSentences = [nltk.word_tokenize(sent) for sent in segmentedSentences]
            posTaggedSentences = [nltk.pos_tag(sent) for sent in tokenizedSentences]
            nerResult = nltk.ne_chunk(posTaggedSentences)
            pathToCopy = 'C:\\Users\\Felipe\\Desktop\\books_txt\\'
            nameToSave = os.path.join(pathToCopy, newName + '.txt')
            newFile = open(nameToSave, 'w')
            newFile.write(nerResult)
            newFile.close()

我收到这些错误:

Traceback (most recent call last):
  File "<pyshell#77>", line 11, in <module>
    nerResult = nltk.ne_chunk(posTaggedSentences)
  File "C:\Python27\lib\site-packages\nltk\chunk\__init__.py", line 177, in ne_chunk
    return chunker.parse(tagged_tokens)
  File "C:\Python27\lib\site-packages\nltk\chunk\named_entity.py", line 116, in parse
    tagged = self._tagger.tag(tokens)
  File "C:\Python27\lib\site-packages\nltk\tag\sequential.py", line 58, in tag
    tags.append(self.tag_one(tokens, i, tags))
  File "C:\Python27\lib\site-packages\nltk\tag\sequential.py", line 78, in tag_one
    tag = tagger.choose_tag(tokens, index, history)
  File "C:\Python27\lib\site-packages\nltk\tag\sequential.py", line 554, in choose_tag
    featureset = self.feature_detector(tokens, index, history)
  File "C:\Python27\lib\site-packages\nltk\tag\sequential.py", line 605, in feature_detector
    return self._feature_detector(tokens, index, history)
  File "C:\Python27\lib\site-packages\nltk\chunk\named_entity.py", line 49, in _feature_detector
    pos = simplify_pos(tokens[index][1])
  File "C:\Python27\lib\site-packages\nltk\chunk\named_entity.py", line 178, in simplify_pos
    if s.startswith('V'): return "V"
AttributeError: 'tuple' object has no attribute 'startswith'

Answer 1

将文本标记为句子然后标记为POS标记,您需要迭代标记句子列表,如下所示:

nerResult = [nltk.ne_chunk(pts) for pts in posTaggedSentences]

而不是这样:

nerResult = nltk.ne_chunk(posTaggedSentences)