Is immutability a general need that should have general solution? By generalizing the idea to lists/tuples, set/frozenset, dicts, and strings (for example), it seems one could simplify the container classes, eliminate code complexity, and perhaps improve resource utilization. mark -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20101124/63bf6de9/attachment-0001.html>