code: def parse_media_range(range):
      
      (type, subtype, params) = parse_mime_type(range)
      if 'q' not in params or not params['q'] or \
              float(params['q']) > 1 or float(params['q']) < 0:
          params['q'] = '1'
      return (type, subtype, params)
docs: Carves up a media range and returns a tuple of the
         (type, subtype, params) where 'params' is a dictionary
         of all the parameters for the media range.
         For example, the media range 'application/*;q=0.5' would
         get parsed into:
  
         ('application', '*', {'q', '0.5'})
  
         In addition this function also guarantees that there 
         is a value for 'q' in the params dictionary, filling it
         in with a proper default if necessary.