Could someone take a look at the patch attached to this bug report? http://python.org/sf/625698 It fixes a problem comparing recursive objects by adding a check in PyObject_RichCompare. Seems to work fine for the specific problem, however, it still doesn't help this case: a = [] b = [] for i in range(2): a.append(a) for i in range(2): b.append(b) print a == b Thanks, Neal