title: Python,sklearn,it-idf how to split by "####",default space
body: <p>use sklean tf-idf,the defult use space split</p>
  
  <pre><code>corpus = [  
  'This is the first document.',  
  'This is the second second document.',  
  'And the third one.',  
  'Is this the first document?'
  ]    
  
  vectorizer = CountVectorizer()   
  X = vectorizer.fit_transform(corpus)
  </code></pre>
  
  <p>but,I want to use this form:</p>
  
  <pre><code>enter code herecorpus = [  
  'This####is####the####first####document.',  
  'This####is####the####second####second####document.'
  ]
  vectorizer = CountVectorizer()   
  X = vectorizer.fit_transform(corpus)
  tfidf=transformer.fit_transform(vectorizer.fit_transform(documents))
  word=vectorizer.get_feature_names()
  weight=tfidf.toarray()
  </code></pre>
  
  <p>How to do?</p>