[Python-Dev] A new dictionary implementation

Mark Shannon mark at hotpy.org
Sun Jan 29 17:07:56 CET 2012

Antoine Pitrou wrote:
> On Sun, 29 Jan 2012 09:56:11 -0500
> Benjamin Peterson <benjamin at python.org> wrote:
>> 2012/1/29 Mark Shannon <mark at hotpy.org>:
>>> Hi,
>>> Now that issue 13703 has been largely settled,
>>> I want to propose my new dictionary implementation again.
>>> It is a little more polished than before.
>> If you're serious about changing the dictionary implementation, I
>> think you should write a PEP. It should explain the new dicts
>> advantages (and disadvantages?) and give comprehensive benchmark
>> numbers. Something along the lines of
>> http://www.python.org/dev/peps/pep-3128/ I should think.
> "New dictionary implementation" is a misnomer here. Mark's patch merely
> allows to share the keys array between several dictionaries. The lookup
> algorithm remains exactly the same as far as I've read. It's actually
> much less invasive than e.g. Martin's AVL trees-for-hash-collisions
> proposal.

Antoine is right. It is a reorganisation of the dict, plus a couple of 
changes to typeobject.c and object.c to ensure that instance 
dictionaries do indeed share keys arrays.
The lookup algorithm remains the same (it works well).


More information about the Python-Dev mailing list