[Python-Dev] Expression optimizations
Steve Holden
steve at holdenweb.com
Tue Feb 10 18:25:51 CET 2009
Daniel Stutzbach wrote:
> On Tue, Feb 10, 2009 at 11:16 AM, Steve Holden <steve at holdenweb.com
> <mailto:steve at holdenweb.com>> wrote:
>
> That's true, but the same *could* be said about the existing
> optimizations for objects that define their own __contains__.
>
>
> No, because there isn't a __not_contains__, so you cannot define the
> inverse operation differently. "not a in b" and "a not in b" have
> exactly the same effects.
>
Ah, right, that guarantees semantic equivalence. Sorry.
regards
Steve
--
Steve Holden +1 571 484 6266 +1 800 494 3119
Holden Web LLC http://www.holdenweb.com/
More information about the Python-Dev
mailing list