python:实现基于NLTK的名词短语提取器
import nltk
from nltk.corpus import brown
import os
brown_train = brown.tagged_sents(categories='news')
regexp_tagger = nltk.RegexpTagger(
[
import nltk
from nltk.corpus import brown
import os
brown_train = brown.tagged_sents(categories='news')
regexp_tagger = nltk.RegexpTagger(
[