title: analyze text file in parallel with mpi4py
body: <p>I have an input tab separated text file:</p>
  
  <pre><code>0   .4
  1   .9
  2   .2
  3   .12
  4   .55
  5   .98
  </code></pre>
  
  <p>I analyze it in plain Python as:</p>
  
  <pre><code>lines = open("songs.tsv").readlines()
  
  def extract_hotness(line):
          return float(line.split()[1])
  
  songs_hotness =map(extract_hotness, lines)
  max_hotness = max(songs_hotness)
  </code></pre>
  
  <p>How do I perform the same operation in parallel using <code>mpi4py</code>?
  I started implementing this with <code>scatter</code>, but that won't work straight away because <code>scatter</code> needs list elements to be the same length as the number of nodes. </p>