title: how to add a item in a list of list using python
body: <p>Is there any way to add a item to a list of list using python. </p>
  
  <p>As an example there is a list as below:</p>
  
  <pre><code>test_list = [['abc','2'],['cds','333'],['efg']]
  </code></pre>
  
  <p>I want to add a item <code>'444'</code> for the position <code>test_list[2][1]</code>.</p>
  
  <p>At last list should be:</p>
  
  <pre><code>test_list = [['abc','2'],['cds','333'],['efg','444']]
  </code></pre>