title: how to selected vocabulary in scikit CountVectorizer
body: <p>I have used scikit <a href="http://scikit-learn.org/stable/modules/generated/sklearn.feature_extraction.text.CountVectorizer.html" rel="nofollow">CountVectorizer</a> to convert collection of documents into matrix of token counts. I have also used its max_features which considers the top max_features ordered by term frequency across the corpus.</p>
  
  <p>Now I want to analyse my selected corpus, especially I want to know frequency of tokens in selected vocabulary. But I am unable to find an easy way to do it. So kindly help me in this regard.</p>