title: Adding Row with Pandas
body: <p>I am trying to add a row that calculate the difference in percentage from the last two row.</p>
  
  <p>This is my code :</p>
  
  <pre><code>df = pd.DataFrame(data=DAU, columns=['Q', 'DAU'])
  dfm = pd.DataFrame(data=MAU, columns=['Q', 'MAU'])
  
  df['o_cat'] = pd.Categorical(df['Q'], Quarter_Order, ordered=True)
  dfm['o_cat'] = pd.Categorical(dfm['Q'], Quarter_Order, ordered=True)
  
  df = df.sort_values('o_cat')
  dfm = dfm.sort_values('o_cat')
  
  df = df[['Q', 'DAU']]
  df['MAU'] = dfm[['MAU']]
  
  print df
  </code></pre>
  
  <p>This is the result :</p>
  
  <p><a href="https://i.stack.imgur.com/lpoHG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lpoHG.png" alt="enter image description here"></a></p>
  
  <p>And i want to add this row at the end:</p>
  
  <pre><code>5  ,    %  ,   0.41   ,   50
  </code></pre>