title: Python regex split a string by one of two delimiters
body: <p>I wanted to cut up a string of email addresses which may be separated by any combination of commas and white-space.</p>
  
  <p>And I thought it would be pretty straight-forward :</p>
  
  <pre><code>sep = re.compile('(\s*,*)+')
  print sep.split("""a@b.com, c@d.com
  
     e@f.com,,g@h.com""")
  </code></pre>
  
  <p>But it isn't. I can't find a regex that won't leave some empty slots like this :</p>
  
  <pre><code>['a@b.com', '', 'c@d.com', '', 'e@f.com', '', 'g@h.com']
  </code></pre>
  
  <p>I've tried various combinations, but none seem to work. Is this, in fact, possible, with regex?</p>