code: def range_by_score(self, min, max):
          
          data = self.items()
          keys = [r[1] for r in data] 
          start = bisect.bisect_left(keys, min)
          end = bisect.bisect_right(keys, max, start)
          return self._as_set()[start:end]
docs: Return all the elements with score >= min and score <= max
          (a range query) from the sorted set.