[Python-Dev] performance of {} versus dict(), de fmd(**kw): return kw trumps all ; -)

Stefan Behnel stefan_ml at behnel.de
Thu Nov 15 15:58:46 CET 2012

Greg Ewing, 15.11.2012 11:48:
> martin at v.loewis.de wrote:
>> It's faster than calling dict() because the dict code will
>> create a second dictionary, and discard the keywords dictionary.
> Perhaps in the case where dict() is called with keyword
> args only, it could just return the passed-in keyword
> dictionary instead of creating another one?

This should work as long as this still creates a copy of d at some point:

    d = {...}


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