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

[Ethan Furman]

MRAB wrote:
> On 2012-11-14 20:53, Mark Adam wrote:
>> On Wed, Nov 14, 2012 at 1:37 PM, Xavier Morel <catch-all at masklinn.net> 
>> wrote:
>>> On 2012-11-14, at 19:54 , Mark Adam wrote:
>>>>
>>>> Merging of two dicts is done with dict.update.
>>>
>>> No, dict.update merges one dict (or two) into a third one.
>>
>> No.  I think you need to read the docs.
>>
>>>> How do you do it on
>>>> initialization?  This doesn't make sense.
>>>
>>> dict(d1, **d2)
>>
>> That's not valid syntax is it?
>>
> No.
> 
> You can have dict(d1) and dict(**d2), but not dict(d1, **d2).

To (mis-)quote Antoine:
 >--> d1 = {1:2}
 >--> d2 = {'3':4}
 >--> dict(d1, **d2)
 > {1: 2, '3': 4}

Apparently it is valid syntax.  Just make sure you keys for the ** operator are valid strings.  :)

~Ethan~