title: Add a new row to a Pandas DataFrame with specific index name
body: <p>I'm trying to add a new row to the DataFrame with a specific index name <code>'e'</code>.</p>
  
  <pre><code>    number   variable       values
  a    NaN       bank          true   
  b    3.0       shop          false  
  c    0.5       market        true   
  d    NaN       government    true   
  </code></pre>
  
  <p>I have tried the following but it's creating a new column instead of a new row. </p>
  
  <pre><code>new_row = [1.0, 'hotel', 'true']
  df = df.append(new_row)
  </code></pre>
  
  <p>Still don't understand how to insert the row with a specific index. Will be grateful for any suggestions.</p>