[Python-Dev] performance of {} versus dict()

Wed Nov 14 14:43:18 CET 2012

2012年11月14日 <martin at v.loewis.de>:
>> Zitat von Chris Withers <chris at simplistix.co.uk>:
>>>> a_dict = dict(
>> x = 1,
>> y = 2,
>> z = 3,
>> ...
>> )
>>>> What can we do to speed up the former case?
>>> It should be possible to special-case it. Rather than creating
> a new dictionary from scratch, one could try to have the new dictionary
> the same size as the original one, and copy all entries.
>> I also wonder whether the PyArg_ValidateKeywordArguments call is really
> necessary: if this is not a proper keyword dictionary, dict creation
> could still proceed in a reasonable way.

In the common case PyArg_ValidateKeywordArguments should be a simple check.
-- 
Regards,
Benjamin