title: Remove element from tuple in a list
body: <p>I've knocking my head against a wall with this:</p>
  
  <p>Basically what I want is to remove " " items from this list of tuples:</p>
  
  <pre><code>[('650', '724', '6354', '', '', ''), ('', '', '', '650', '723', '4539')]
  </code></pre>
  
  <p>and obtain the following new list:</p>
  
  <pre><code>[('650', '724', '6354'), ('650', '723', '4539')]
  </code></pre>
  
  <p>any ideas?</p>