title: Append JSON elements to a list, then remove duplicates efficiently in Python
body: <p>I have a json file that's like for e.g.</p>
  
  <blockquote>
    <p>[{"fu": "thejimjams", "su":
    232104580}, {"fu": "thejimjams", "su":
    216575430}, {"fu": "thejimjams", "su":
    184695850}]</p>
  </blockquote>
  
  <p>I need to put all the values for a bunch of json files in the "su" category in a list. So each file (about 200) will have their own list, then I'm going to combine the list and remove duplicates. Is there and advisable while I go about doing this to save system resources and time?</p>
  
  <p>I'm thinking of making a list, loop through the json file get each "su" put it on a list go to the next file then append list, then scan through to remove duplicates.</p>
  
  <p>In terms of removing the duplicates I'm thinking of following what the answer was on this question: <a href="https://stackoverflow.com/questions/1319338/combining-two-lists-and-removing-duplicates-without-removing-duplicates-in-origi">Combining two lists and removing duplicates, without removing duplicates in original list</a> unless that's not efficient</p>
  
  <p>Basically open to recommendations about a good way to implement this.</p>
  
  <p>Thanks,</p>