>From the Zen of Python: > In the face of ambiguity, refuse the temptation to guess.
I believe the reason something isn't already done to break cycles is that the authors of the cyclic garbage collector considered the above aphorism. They rely on the author of the code with the cycles to figure out how to break them. All I was suggesting was that Python could provide a hook where the programmer could codify his algorithm for breaking cycles. Skip -- http://mail.python.org/mailman/listinfo/python-list
