why () is () and [] is [] work in other way?

[Robert Kern]

On 4/24/12 1:03 AM, Tim Delaney wrote:
> On 24 April 2012 09:08, Devin Jeanpierre <jeanpierreda at gmail.com
> <mailto:jeanpierreda at gmail.com>> wrote:
>
>     On Mon, Apr 23, 2012 at 6:26 PM, Tim Delaney
>     <timothy.c.delaney at gmail.com <mailto:timothy.c.delaney at gmail.com>> wrote:
>      > And doing that would make zero sense, because it directly contradicts the
>      > whole *point* of "is". The point of "is" is to tell you whether or not two
>      > references are to the same object. This is a *useful* property.
>
>     It's useful for mutable objects, yes. How is it useful for immmutable
>     things? They behave identically everywhere where you don't directly
>     ask the question of "a is b" or "id(a) == id(b)".
>
>
> Not always. NaNs are an exception - they don't even compare equal to themselves.
> And hence a very good reason why "is" and == are separate operations.

I think you misread what Devin wrote. "id(a) == id(b)" not "a == b".

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco