code: def iterpws(self, n):
          
          for _id in np.argsort(self._freq_list)[::-1][:n]:
              pw = self._T.restore_key(_id)
              if self._min_pass_len <= len(pw) <= self._max_pass_len:
                  yield _id, pw, self._freq_list[_id]
docs: Returns passwords in order of their frequencies.
          @n: The numebr of passwords to return
          Return: pwid, password, frequency
          Every password is assigned an uniq id, for efficient access.