title: How to delete parts of a file in python?
body: <p>I have a file named a.txt which looks like this:</p>
  
  <blockquote>
    <p>I'm the first line<br>
    I'm the second line.<br>
    There may be more lines here.  </p>
    
    <p>I'm below an empty line.<br>
    I'm a line.<br>
    More lines here.</p>
  </blockquote>
  
  <p>Now, I want to remove the contents above the empty line(including the empty line itself).
  How could I do this in a Pythonic way?</p>