title: finding the difference between two different data frame by using pd
body: <pre><code>df = pd.DataFrame({&quot;Columns1&quot;:[A, B, C, D]})
  
  df2 = pd.DataFrame({&quot;Columns1&quot;:[A, B, C]})
  </code></pre>
  <p>As you seen the difference between two data frame is D becouse it is in df and there is not in df2</p>
  <p>how can i use pandas or other to find the difference and replace it in new data frame ?</p>