How to provide (or generate) tags for nltk lemmatizers
问题 I have a set of documents, and I would like to transform those into such form, that it would allow me to count tfidf for words in those documents (so that each document is being represented by vector of tfidf-numbers). I thought that it is enough to call WordNetLemmatizer.lemmatize(word), and then PorterStemmer - but all 'have', 'has', 'had', etc are not being transformed to 'have' by the lemmatizer - and it goes for other words as well. Then I have read, that I am supposed to provide a hint