code: def create_order_keyword_list(keywords):
       
      result = []
      for keyword in keywords:
          result.append((keyword, ''))
          result.append(('-%s' % keyword, ''))
      return result
docs: Takes a given keyword list and returns a ready-to-go
      list of possible ordering values.
  
      Example: ['foo'] returns [('foo', ''), ('-foo', '')]