I believe that 'is' tests equality of reference, such that >>> a = range(1,3) >>> b = range(1,3) >>> a is b False
The 'is' operator tells you whether a and b refer to the same object. What I've been discussing is whether == should test for "structural" equality so that a and b remain equivalent under parallel mutations (and also under single mutations to common references) Cheers, Mike Maric Michaud wrote: > Le Jeudi 01 Juin 2006 18:00, [EMAIL PROTECTED] a écrit : > > Perhaps the most fundamental notion is mathematics is that the left and > > right sides of an equation remain identical after any operation applied > > to both sides. > > IMHO, you are not aware that the '=' symbol of mathematics exists in python, > it's the 'is' assertion. > > a is b > and then, do what you want with a (or b), a is b remains True. > > THIS is the meaning of expr1 = expr2, but in computer science, this is not as > important as it is in pure logic (most languages do not even provide the 'is' > assertion). > > -- > _____________ > > Maric Michaud > _____________ > > Aristote - www.aristote.info > 3 place des tapis > 69004 Lyon > Tel: +33 426 880 097 -- http://mail.python.org/mailman/listinfo/python-list
