code: def splittag(url):
      
      global _tagprog
      if _tagprog is None:
          import re
          _tagprog = re.compile('^(.*)#([^#]*)$')
  
      match = _tagprog.match(url)
      if match: return match.group(1, 2)
      return url, None
docs: splittag('/path#tag') --> '/path', 'tag'.