《Python自然语言处理》用nltk.download()的方法安装书中所用语料库数据，不太好使。一是部分网友反映的下载很慢很慢，二是下载链接，无论书上、NLTK官网（http://nltk.org/nltk_data/）、网友博客（http://www.cnblogs.com/ToDoToTry/archive/2013/01/18/2865941.html）提供的，都已年久失修，试试改了改旧链接找到了NLTK Corpus，应该比书中所用的数据集更多，列出如下方便大家参考:
1) NLTK Corpora: http://www.nltk.org/nltk_data/. 语料库没有打包在一起，需要哪个下哪个。
2) Github: https://github.com/nltk/nltk_data/tree/gh-pages。整个一个340M多的Zip，解压出corpora文件夹，放到nltk默认nltk_data所在文件夹c:\nltk_data下就都OK啦。如要换默认位置要在环境变量里做修改，具体看官网http://www.nltk.org/data.html。
按照官网http://www.nltk.org/data.html和书上的例子各做了test，验证nltk_data可用：
>>> from nltk.corpus import brown >>> brown.words() ['The', 'Fulton', 'County', 'Grand', 'Jury', 'said', ...] >>> from nltk.book import * *** Introductory Examples for the NLTK Book *** Loading text1, ..., text9 and sent1, ..., sent9 Type the name of the text or sentence to view it. Type: 'texts()' or 'sents()' to list the materials. text1: Moby Dick by Herman Melville 1851 text2: Sense and Sensibility by Jane Austen 1811 text3: The Book of Genesis text4: Inaugural Address Corpus text5: Chat Corpus text6: Monty Python and the Holy Grail text7: Wall Street Journal text8: Personals Corpus text9: The Man Who Was Thursday by G . K . Chesterton 1908 >>>
