On Jun 18, 7:26 am, "Gabriel Genellina" <[EMAIL PROTECTED]> wrote: > En Tue, 17 Jun 2008 09:09:41 -0300, Derek Martin <[EMAIL PROTECTED]> > escribió: > > > On Tue, Jun 17, 2008 at 04:33:03AM -0300, Gabriel Genellina wrote: > >> > Basically 'a is b' and 'not(a is b)' is similar to 'id(a) == id(b)' > >> > and 'not(id(a) == id(b))' > > >> No. > > > Sure it is... he said "similar"... not identical. They are not the > > same, but they are similar. > > 'equality' and 'identity' are similar too, so the whole answer would make > no sense in that case. You can't explain identity based on things that > aren't identical. A fine grained question for a fine grained difference > requires a fine grained answer.
In my defense, I admit I have the tendency to forget (purposefully) fine-grained differences if I thought that the difference was not significant enough in the context of speaking. The OP asked about != and 'is not', so I explained in terms of those being equality and identity testing respectively. To give a more concise and easy to understand example, I said that 'is not' is like using testing the 'id()' of the objects. Since (I think) the difference between != and 'is not' is much larger compared to the difference between 'is not' and 'id() test', I thought I could consider 'is not' and 'id() test' as "equivalent" in the context of this thread: 'Does != is equivalent to "is not"'. Either way, I'm sorry that I failed to put explicit notice that 'is not' and 'id() testing' isn't exactly the same either. > > Saying a flat "no" alone, without qualifying your statement is > > generally interpreted as rude in English... It's kind of like how you > > talk to children when they're too young to understand the explanation. > > Yucky. > > I didn't meant to be rude at all - and I apologize to Mr. Lie. I don't deserve the apology because the mistake is on me and I didn't feel offended, in fact I'm delighted someone could point out my mistake. > The > explanation for such strong "No" was in the paragraph below it (the idea > was to say: "No to this, yes to that") -- http://mail.python.org/mailman/listinfo/python-list
