title: File cannot be read after regex operation (Python)
body: <p>I am trying out regex operations in Python. However, I am not able to read the file again once I use it for the same. </p>
  
  <pre><code>f = codecs.open(filename, 'rU', 'utf-8')
  #print f.read() works here
  
  #printing the year
  year = re.search(r'Popularity in (\w+)',f.read())
  print year.group(1)
  
  #now, this returns nothing !
  print f.read()
  </code></pre>
  
  <p>I am not able to understand what I am doing wrong here.</p>