title: Comparing all columns on two pandas dataframes to get the difference
body: <p>I have two pandas dataframes. Lets say the first one is <code>master</code></p>
  
  <pre><code>ID  COL1    COL2
  1   A       AA
  2   B       BB
  3   C       CC
  4   D       DD
  </code></pre>
  
  <p>And  another one <code>source</code></p>
  
  <pre><code>ID  COL1    COL2
  1   A       ZZ
  2   B       BB
  3   YY      CC
  5   G       GG
  6   H       HH
  </code></pre>
  
  <p>Evidently the length can be different and the difference can be in more than one column. However, the structure will be the same. I want to find the records in the <code>source</code> that are either new or different from what is available in <code>master</code>. That is, the output I am looking for is a dataframe:</p>
  
  <pre><code>ID  COL1    COL2
  1   A       ZZ
  3   YY      CC
  5   G       GG
  6   H       HH
  </code></pre>
  
  <p>I tried solutions in:</p>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/17095101/outputting-difference-in-two-pandas-dataframes-side-by-side-highlighting-the-d">Outputting difference in two Pandas dataframes side by side - highlighting the difference</a></li>
  <li><a href="https://stackoverflow.com/questions/20225110/comparing-two-dataframes-and-getting-the-differences">Comparing two dataframes and getting the differences</a></li>
  </ul>
  
  <p>But none of those seems to be working for me. This is basically trying to find out what's new.</p>