title: Python - Remove rows from CSV files based on column criteria
body: <p>I need to return ONLY first of each 'status' every time the status changes.  Here is an excerpt, for example from this data set I would only need rows 1,2,5,6,8,10,11,12,13,15,18,19,21.  </p>
  
  <pre><code>Row,Serial Number,Time,Status 
  1,1400004,3/10/2014 11:52,GREEN 
  2,1400004,3/15/2014 11:45,YELLOW 
  3,1400004,3/29/2014 7:59,YELLOW 
  4,1400004,4/16/2014 15:59,YELLOW 
  5,1400004,5/10/2014 8:18,GREEN 
  6,1400004,5/11/2014 15:28,YELLOW 
  7,1400004,5/24/2014 7:56,YELLOW 
  8,1400004,5/26/2014 7:59,GREEN 
  9,1400004,5/28/2014 8:26,GREEN 
  10,1400004,6/13/2014 17:29,YELLOW 
  11,1400004,6/15/2014 15:12,GREEN 
  12,1400004,6/17/2014 8:57,YELLOW 
  13,1400007,1/3/2014  11:55,GREEN 
  14,1400007,1/18/2014 5:35,GREEN 
  15,1400007,1/18/2014 18:32,YELLOW 
  16,1400007,1/19/2014 21:50,YELLOW 
  17,1400007,1/21/2014 10:56,YELLOW 
  18,1400007,1/27/2014 8:15,GREEN 
  19,1400007,2/6/2014  9:47,YELLOW 
  20,1400007,2/12/2014 12:44,YELLOW 
  21,1400007,2/18/2014 12:40,GREEN 
  22,1400007,2/24/2014 12:08,YELLOW 
  </code></pre>
  
  <p>Here is my code, I'm close but its off a bit. </p>
  
  <pre><code>import csv
  with open('NEW2.csv', 'rb') as f:
      csv_input = csv.reader(f)
      entries = []
      for x in csv_input:
          if x[3] == csv_input.next()[3]:
              pass
          else:
              entries.append(x)
      print entries
  </code></pre>