您是否遇到了以下代码片段？
english_vocab = set(w.lower() for w in nltk.corpus.words.words())text_vocab = set(w.lower() for w in text if w.lower().isalpha())unusual = text_vocab.difference(english_vocab)
来自http://groups.google.com/group/nltk-
users/browse_thread/thread/a5f52af2cbc4cfeb?pli=1&safe=active
还是以下演示文件？
https://web.archive.org/web/20120202055535/http://pre.google.com/p/nltk/source/browse/trunk/nltk_contrib/nltk_contrib/misc/langid.py
