On Mon, Apr 23, 2012 at 11:01 AM, Paul Rubin <no.email@nospam.invalid> wrote: > Kiuhnm <kiuhnm03.4t.yahoo.it> writes: >> I can't think of a single case where 'is' is ill-defined. > > If I can't predict the output of > > print (20+30 is 30+20) # check whether addition is commutative > print (20*30 is 30*20) # check whether multiplication is commutative > > by just reading the language definition and the code, I'd have to say > "is" is ill-defined.
It seems to me that one could equally argue that "+" is ill-defined, because the output of "x + y" could just as easily be 1729 or 42. In either case the problem is not in the operator, but in determining exactly what the left and right sides evaluate to. -- http://mail.python.org/mailman/listinfo/python-list
