title: Comparing two excel file with pandas
body: <p>I have two excel file, A and B. A is Master copy where updated record of employee Name and Organization Name (<code>Name</code> and <code>Org</code>) is available. File B contains <code>Name</code> and <code>Org</code> columns with bit older record and many other columns which we are not interested in. </p>
  
  <pre><code>   Name      Org
  0   abc    ddc systems
  1   sdc    ddc systems
  2   csc    ddd systems
  3   rdc    kbf org
  4   rfc    kbf org
  </code></pre>
  
  <p>I want to do two operation on this:</p>
  
  <p>1) I want to compare Excel B (column <code>Name</code> and <code>Org</code>) with Excel A (column <code>Name</code> and <code>Org</code>) and update file B with all the missing entries of <code>Name</code> and corresponding <code>Org</code>.</p>
  
  <p>2) For all existing entries in File B (column <code>Name</code> and <code>Org</code>), I would like to compare file and with file A and update <code>Org</code> column if any employee organization has changed. </p>
  
  <p>For Solution 1) to find the new entries tried below approach (Not sure if this approach is correct though), output is tuple which I was not sure how to update back to <code>DataFrame</code>. </p>
  
  <pre><code>diff = set(zip(new_df.Name, new_df.Org)) - set(zip(old_df.Name, old_df.Org))
  </code></pre>
  
  <p>Any help will be appreciated. Thanks.</p>