title: Removing duplicates from list of lists in Python
body: <p>Can anyone suggest a good solution to remove duplicates from nested lists if wanting to evaluate duplicates based on first element of each nested list?</p>
  
  <p>The main list looks like this:</p>
  
  <pre><code>L = [['14', '65', 76], ['2', '5', 6], ['7', '12', 33], ['14', '22', 46]]
  </code></pre>
  
  <p>If there is another list with the same element at first position <code>[k][0]</code> that had already occurred, then I'd like to remove that list and get this result:</p>
  
  <pre><code>L = [['14', '65', 76], ['2', '5', 6], ['7', '12', 33]]
  </code></pre>
  
  <p>Can you suggest an algorithm to achieve this goal?</p>