title: Removing duplicates from tuples within a list
body: <p>I have a list of tuples: </p>
  
  <pre><code>lst = [('a','b'), ('c', 'b'), ('a', 'd'), ('e','f'), ('a', 'b')]
  </code></pre>
  
  <p>I want the following output list:</p>
  
  <pre><code>output = [('a','b'), ('e','f')]
  </code></pre>
  
  <p>i.e I want to compare the elements of first tuple with remaining tuples and remove the tuple which contains either one or more duplicate elements. </p>
  
  <p>My attempt: </p>
  
  <p>I was thinking of using for loops, but that wont be feasible once i have very large list. I browsed through following posts but could not get the right solution:</p>
  
  <p><a href="https://stackoverflow.com/questions/4009304/removing-duplicates-members-from-a-list-of-tuples">Removing duplicates members from a list of tuples</a>
  <a href="https://stackoverflow.com/questions/480214/how-do-you-remove-duplicates-from-a-list-in-python-whilst-preserving-order">How do you remove duplicates from a list in whilst preserving order?</a></p>
  
  <p>If somebody could guide me the right direction, it will be very helpful. Thanks! </p>