title: libsass-python compile a file
body: <p>I recently find a fantastic python library compiling SASS really fast!
  <a href="https://github.com/dahlia/libsass-python" rel="nofollow">libsass-python</a> seems to be very good and really fast</p>
  
  <p>How I can use it to watch for any change in a sass folder or file and compile it in CSS ?
  I do not understand how to pass a file and how to use --watch option</p>
  
  <p>Thanks!</p>