title: Pandas DataFrames add square brackets to specific column values
body: <p>how to add sqaure backets to specif column values.</p>
  <p>like in DataFrame if I have 2 columns</p>
  <ol>
  <li><p>Name</p>
  </li>
  <li><p>country</p>
  <pre><code>Name               country
  
  Ali                UK,USA
  Sara               UK,Canada
  Tom                Australia,Canada
  </code></pre>
  </li>
  </ol>
  <p>how I can add the square brackets to the values of column country.</p>
  <p>Like:</p>
  <pre><code>       Name               country
  
     Ali                [UK,USA]
     Sara               [UK,Canada]
     Tom                [Australia,Canada]
  </code></pre>