> As I understand it there are no cases where obj==None and obj is None > will give different results (which is not true for == vs is in > general), so is there any practical difference? Maybe you save a > handful of cycles?
as far as i know, that's it. but if this comparison happens a *lot* in your code, it starts to add up. for the newbies, just remember that "==" is an object *value* comparison vs. 'is' which is an object *identity* comparison. the former requires pulling out the values of both objects and doing a comparison while the latter is just checking the references to see if both are looking at exactly the same object (IDs match) so there's no need to fetch their values. -wesley ps. danny's example is pretty scary tho... _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
