title: using python commenting xml tags
body: <p>for the below xml file , how can i comment(in xml) the heading tag including its children using python ? i am new to python , tried using lxml but only able to add a new comment, not able to comment existing tags. please do help , thanks in advance</p>
  
  <pre><code>&lt;note&gt;
  &lt;to&gt;Tove&lt;/to&gt;
  &lt;from&gt;Jani&lt;/from&gt;
  &lt;heading&gt; Reminder
      &lt;security&gt;level  1&lt;/security&gt;
  &lt;/heading&gt;
  &lt;body&gt;Don't forget me this weekend!&lt;/body&gt;
  &lt;/note&gt;
  </code></pre>
  
  <p>i would want the output to be like</p>
  
  <pre><code>&lt;note&gt;
  &lt;to&gt;Tove&lt;/to&gt;
  &lt;from&gt;Jani&lt;/from&gt;
  &lt;!--  &lt;heading&gt; Reminder
      &lt;security&gt;level  1&lt;/security&gt;
  &lt;/heading&gt; --&gt;
  &lt;body&gt;Don't forget me this weekend!&lt;/body&gt;
  &lt;/note&gt;
  </code></pre>