title: Remove Duplicates in two-dimensional array while maintaining sequence
body: <p>I have found a lot of threads on removing duplicates in arrays but none for my specific use-case. I have a two-dimensional list that I need to remove duplicates from however I must maintain the original sequence</p>
  
  <pre><code>mylist = [['Installation', '64%'], ['C2', '14%'], ['NA', '14%'], ['C2', '14%'], ['NA', '14%'], ['na', '7%']]
  </code></pre>
  
  <p>I need to simply drop the duplicates without re-arranging, so..</p>
  
  <pre><code>newlist = [['Installation', '64%'], ['C2', '14%'], ['NA', '14%'], ['na', '7%']]
  </code></pre>
  
  <p>appreciate any help</p>