title: Sort list of list in Python according to a specific column
body: <p>I have a list of lists that looks like this:</p>
  
  <pre><code>l = [[1, 2, 3], 
       [3, 5, 4], 
       [9, 8, 7]]
  </code></pre>
  
  <p>I want to sort corresponding elements in each sublist so that the <em>middle sublist</em> would be in descending order, which would result in:</p>
  
  <pre><code>l = [[2, 3, 1],
       [5, 4, 3], 
       [8, 7, 9]]
  </code></pre>
  
  <p>The second list is now descending: <code>[5, 4, 3]</code>. Essentially, I want reorder the vertical columns in that 2D representation. It seems like an easy task, but I had difficulties finding a solution.</p>
  
  <p>So far I tried:</p>
  
  <pre><code>from operator import itemgetter
  sorted(l, key=itemgetter(1))
  </code></pre>
  
  <p>which didn't change anything and I tried</p>
  
  <pre><code>print(l.sort(key = lambda row: (row[1])))
  </code></pre>
  
  <p>which gave None.</p>