title: Filter unique values in csv and add count as a new column
body: <p>I have a very large csv (50 millions records more or less) file with different columns like: </p>
  
  <pre><code>id, state, city, origin, destination, url, type
  </code></pre>
  
  <p>In this file, I want to check each repeated value, I mean all rows that have exactly the same columns value, remove the duplicates and then add a new column with the repeated number.</p>
  
  <p>For example if I have </p>
  
  <pre><code>id, state, city, origin, destination, url, type
  1, NY, NY, manhattan, times square, http:ny.com, taxi
  1, NY, NY, manhattan, times square, http:ny.com, taxi
  1, NY, NY, manhattan, times square, http:ny.com, taxi
  1, NY, NY, manhattan, times square, http:ny.com, taxi
  </code></pre>
  
  <p>I want to output this </p>
  
  <pre><code>id, state, city, origin, destination, url, type, count
  1, NY, NY, manhattan, times square, http:ny.com, taxi, 4
  </code></pre>
  
  <p>Where count is the number of times this column is repeated.
  I know some javascript but not Python, however I am willing to use any tool as long as I can create a new file with the new values and columns.</p>