[Python-Dev] A new dictionary implementation (original) (raw)

Mark Shannon mark at hotpy.org
Thu Feb 2 20:17:16 CET 2012

Just a quick update.

I've been analysing and profile the behaviour of my new dict and messing about with various implementation options.

I've settled on a new implementation. Its the same basic idea, but with better locality of reference for unshared keys.

Guido asked:

Another question: a common pattern is to use (immutable) class variables as default values for instance variables, and only set the instance variables once they need to be different. Does such a class benefit from your improvement?

For those instances which keep the default, yes. Otherwise the answer is, as Martin pointed out, it could yes provided that adding a new key does not force a resize. Although it is a bit arbitrary when a resize occurs. The new version will incorporate this behaviour.

Expect version 2 soon.

Cheers, Mark.

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