title: Python list comprehension "too many values to unpack"
body: <p>sorry for this question but I'm drive crazy with the error "too many values to unpack". This is the code</p>
  
  <pre><code>FREQ = 3
  fourgrams=""
  n = 4
  tokens = token_text(text) # is a function that tokenize
  fourgrams = ngrams(tokens, n)
  final_list = [(item,v) for item,v in nltk.FreqDist(fourgrams) if v &gt; FREQ]
  print final_list
  </code></pre>
  
  <p>Where is the error? Thanks a lot</p>