title: Diff of two Dataframes
body: <p>I need to compare two dataframes of different size row-wise and print out non matching rows. Lets take the following two:</p>
  <pre><code>df1 = DataFrame({
  'Buyer': ['Carl', 'Carl', 'Carl'],
  'Quantity': [18, 3, 5, ]})
  
  df2 = DataFrame({
  'Buyer': ['Carl', 'Mark', 'Carl', 'Carl'],
  'Quantity': [2, 1, 18, 5]})
  </code></pre>
  <p>What is the most efficient way to row-wise over df2 and print out rows not in df1 e.g.</p>
  <pre><code>Buyer     Quantity 
  Carl         2
  Mark         1
  </code></pre>
  <p>Important: I do not want to have row:</p>
  <pre><code>Buyer     Quantity 
  Carl         3
  </code></pre>
  <p>Included in the diff:</p>
  <p>I have already tried:
  <a href="https://stackoverflow.com/questions/32972856/comparing-two-dataframes-of-different-length-row-by-row-and-adding-columns-for-e">Comparing two dataframes of different length row by row and adding columns for each row with equal value</a>
  and <a href="https://stackoverflow.com/questions/17095101/outputting-difference-in-two-pandas-dataframes-side-by-side-highlighting-the-d">Compare two DataFrames and output their differences side-by-side</a></p>
  <p>But these do not match with my problem.</p>