> Other Python libraries exist which attempt to do similar things, of course; PyCells and Cellulose are two. However, only the Trellis supports fully circular rules (like the temperature conversion example above), and intra-pulse write conflict detection. The Trellis also uses less memory for each cell (rule/value object), and offers many other features that either PyCells or Cellulose lack.

I believe PJE was the mentor for PyCells and Trellis is PJE's take on the problem. I was following PyCells from its announcement since it seemed useful and if PJE isn't the mentor, he was heavily consulted.