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

[Antoine Pitrou]

On Wed, 14 Nov 2012 14:53:11 -0600
Mark Adam <dreamingforward at gmail.com> 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?

Why don't you try it for yourself:

>>> d1 = {1:2}
>>> d2 = {3:4}
>>> dict(d1, **d2)
{1: 2, 3: 4}