[Python-Dev] Counting collisions for the win (original) (raw)

Lennart Regebro regebro at gmail.com
Sun Jan 22 20:53:41 CET 2012

On Sun, Jan 22, 2012 at 11:11, Victor Stinner <victor.stinner at haypocalc.com> wrote:

This seed is chosen randomly at runtime, but cannot change once chosen. The hash is used to compare objects: if hash(obj1) != hash(obj2), objects are considered different. So two strings must have the same hash if their value is the same.

Salt could also be an appropriate term here, but since salt is generally changed on a per-use basis (a single process may use many different salts), seed is more correct, since this value is only chosen once per process. We may use a different salt per dictionary.

Can we do that? I was thinking of ways to not raise errors when we get over a collision count, but instead somehow change the way the dictionary behaves when we get over the collision count, but I couldn't come up with something. Somehow adding a salt would be one possibility. But I don't see how it's doable except for the string-keys only case mentioned before.

But I might just be lacking imagination. :-)

//Lennart

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