Steve Holden <[EMAIL PROTECTED]> wrote: ... > > 3. If two objects are equal with "==", does that > > mean their values are the same? > > Almost universally, yes, although if you know enough about how the > interpreter works "under the hood" you can define the response of > instances of your own classes to the "==" operator (by defining their > __eq__ method), and even define a class whose instances aren't equal to > anything, even to themselves!
Hmmm... now this may be just be, but I'm quite vary of saying that, since 1 == 1.0 == 1.0+0j, those three objects's values "are the same". "Are equal", sure. But I intuitively see "being the same" as a stronger condition than "being equal". In mathematics, 1 is not "the same" as 1.0 -- there exists a natural morphism of integers into reals that _maps_ 1 to 1.0, but they're still NOT "the same" thing. And similarly for the real-vs-complex case. Python may differ -- try using those "equal but not the same numbers" as keys into the same dict, and see. One of the few *surprises* I ever got from Python...!-) ((I don't think this violates the "introduce no complexity that doesn't help understanding" rule -- I think the 1==1.0 case is important!)) Alex -- http://mail.python.org/mailman/listinfo/python-list
