code: def splithost(url):
      
      global _hostprog
      if _hostprog is None:
          import re
          _hostprog = re.compile('^//([^/?]*)(.*)$')
  
      match = _hostprog.match(url)
      if match:
          host_port = match.group(1)
          path = match.group(2)
          if path and not path.startswith('/'):
              path = '/' + path
          return host_port, path
      return None, url
docs: splithost('//host[:port]/path') --> 'host[:port]', '/path'.