"/a" is not "/a" ?
Lie Ryan
lie.1296 at gmail.com
Sat Mar 7 05:18:52 EST 2009
Steven D'Aprano wrote:
> Albert Hopkins wrote:
>
>> I would think (not having looked) that the implementation of == would
>> first check for identity (for performance reasons)...
>
> For some types, it may. I believe that string equality testing first tests
> whether the two strings are the same string, then tests if they have the
> same hash, and only then do a character-by-character comparison. Or so I've
> been told.
>
>> can an object be identical but not equal to itself?
>
> Yes. Floating point NANs are required to compare unequal to all floats,
> including themselves. It's part of the IEEE standard.
btw, have anybody noticed that the subject line "/a" is not "/a" is
actually False.
>>> "/a" is not "/a"
False
>>> a = "/a"
>>> b = "/a"
>>> a is not b
True
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