title: Python Count Unique value in Row csv
body: <p>I have CSV, which is in a list. 
  Example:</p>
  
  <pre><code>[[R2C1,R01,API_1,801,API_TEST01],
  [R2C1,R01,API_1,802,API_TEST02],
  [R2C1,R01,API_1,801,API_TEST03]]
  </code></pre>
  
  <p>Like to find out the all the unique in <code>i[3]</code> and count them. 
  results:</p>
  
  <pre><code>[{num: 801, count: 2}, {num: 802, count: 1}]
  </code></pre>
  
  <p>so that I can call <code>dict</code> key for another test. </p>
  
  <p>Code:</p>
  
  <pre><code>    for row in data[1:]:
      vnum = row[3]
      ipcount.append({"num":vnum,"count": count})
      if row[3] not in ipcount:
          ipcount.append({"num":vlan})
  </code></pre>