On Fri, 2005-10-07 at 10:33, [EMAIL PROTECTED] wrote: > In fact, i want to sort the list based on the 'allocated attribute' and > at the same time, test membership based on the id attribute. > __cmp__ logically implies an ordering test, not an identity test. These > two notions seems to be confounded in python which is unfortunate. Two > objects could have the same rank while still being different. > Alain
You could use the id in __cmp__ as a tie-breaker if the two objects have equal "allocated" values. By the way, __cmp__ is not an identity test. The "in" operator doesn't use object identity, it uses object equality, and __cmp__ does serve to test object equality (if no __eq__ method is present). Perhaps the following example will clarify the behavior of "in": >>> A = [1] >>> B = [1] >>> A==B True >>> A is B False >>> A in ["spam", 42, B] True HTH, Carsten Haese. -- http://mail.python.org/mailman/listinfo/python-list
