Planning a Python Course for Beginners
Gregory Ewing
greg.ewing at canterbury.ac.nz
Thu Aug 10 19:18:57 EDT 2017
Steve D'Aprano wrote:
> On Thu, 10 Aug 2017 07:00 pm, Peter Otten wrote:
>
>> /* bottom 3 or 4 bits are likely to be 0; rotate y by 4 to avoid
>> excessive hash collisions for dicts and sets */
>
> which I think agrees with my comment: using the id() itself would put too many
> objects in the same bucket (i.e. too many collisions).
I suspect this is more of a minor performance tweak than a vital
issue. Otherwise it would mean that dict's algorithm for
assigning items to buckets based on the hash isn't all that
great.
--
Greg
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