Answer by sel for n-grams in python, four, five, six grams?

For four_grams it is already in NLTK, here is a piece of code that can help you toward this:

 from nltk.collocations import * import nltk #You should tokenize your text text = "I do not like green eggs and ham, I do not like them Sam I am!" tokens = nltk.wordpunct_tokenize(text) fourgrams=nltk.collocations.QuadgramCollocationFinder.from_words(tokens) for fourgram, freq in fourgrams.ngram_fd.items():         print fourgram, freq

I hope it helps.