On Fri, Dec 30, 2016 at 9:29 AM, <j...@math.brown.edu> wrote: > Updating the docs sounds like the more important change for now, given 3.7+. > But before the docs make an official recommendation for that recipe, were > the analyses that Steve and I did sufficient to confirm that its hash > distribution and performance is good enough at scale, or is more rigorous > analysis necessary? > > I've been trying to find a reasonably detailed and up-to-date reference on > Python hash() result requirements and analysis methodology, with > instructions on how to confirm if they're met, but am still looking. Would > find that an interesting read if it's out there. But I'd take just an > authoritative thumbs up here too. Just haven't heard one yet.
I'm not an expert on hash table implementation subtleties, but I can quote Objects/dictobject.c: "Most hash schemes depend on having a "good" hash function, in the sense of simulating randomness. Python doesn't ..." https://github.com/python/cpython/blob/d0a2f68a5f972e4474f5ecce182752f6f7a22178/Objects/dictobject.c#L133 (Basically IIUC the idea is that Python dicts use a relatively sophisticated probe sequence to resolve collisions which allows the use of relatively "poor" hashes. There are interesting trade-offs here...) -n -- Nathaniel J. Smith -- https://vorpus.org _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
