title: How do I convert URL in a plain text to clickable links using python?
body: <p>I have plain text, for example, take into account the following sentence :</p>
  
  <blockquote>
    <p>I was surfing www.google.com and I found an interesting site <a href="http://www.stackoverflow.com">www.stackoverflow.com</a>. It's amazing!</p>
  </blockquote>
  
  <p>In above example, www.google.com is a plain text, which I need to be converted like <a href="http://www.google.com" rel="nofollow">www.google.com</a> (wrapped within anchor tag, having link to google.com). While, www.stackoverflow.com is already within anchor tag, which I want to keep intact. How can I do this using Python regular-expression ? </p>