[Python-ideas] Adding "+" and "+=" operators to dict

[Neil Girdhar]

Can't "|" return a view?

On Thursday, February 12, 2015 at 9:53:12 AM UTC-5, Petr Viktorin wrote:
>
> I don't see ChainMap mentioned in this thread, so I'll fix that:
>
> On Thu, Feb 12, 2015 at 2:32 PM, Juancarlo Añez <apa... at gmail.com 
> <javascript:>> wrote:
>
> > most common cases would be:
> >
> >
> >     new_dict = a + b
> >     old_dict += a
>
> In today's Python, that's:
> from collections import ChainMap
> new_dict = dict(ChainMap(b, a))
> old_dict.update(a)
>
> >>     new_dict = {}
> >>     for old_dict in (a, b, c, d):
> >>         new_dict.update(old_dict)
> >
> >
> > It would be easier if we could do:
> >
> >     new_dict = {}
> >     new_dict.update(a, b, c, d)
> >
> > It would also be useful if dict.update() returned self, so this would be
> > valid:
> >
> >     new_dict = {}.update(a, b, c, d)
>
> In today's Python:
> new_dict = dict(ChainMap(d, b, c, a))
>
> Many uses don't need the dict() call – e.g. when passing it **kwargs,
> or when it's more useful as a view.
>
> Personally, the lack of a special operator for this has never bothered me.
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