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

[Benjamin Peterson]

2012/11/14  <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