Sybren Stuvel <[EMAIL PROTECTED]> wrote: > Dan Bishop enlightened us with: > >>>> a = b = 1e1000 / 1e1000 > >>>> a is b > > True > >>>> a == b > > False > > If "a is b" then they refer to the same object, hence a == b. It > cannot be otherwise, unless Python starts to defy logic. I copied your
Python also needs to respect standards (such as IEEE 754 for floating-point arithmetic, and the SQL standards) which do specify the existence of special objects that "are not equal to anything" including themselves -- Nan and NULL respectively for these two standards. We're talking about extremely widespread international standards developed by huge body of professionals which do include professional logicians, so I doubt they "defy logic". Python tries to delegate FP to the underlying hardware and SQL to an external relational DB engine, so it should be as compliant as the pieces of infrastructure it's using -- which seems to me to be a good architectural decision (not just for speed and ease of coding, but to ensure any anomaly is somebody else's fault:-). Alex -- http://mail.python.org/mailman/listinfo/python-list
