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

[Juancarlo Añez]

On Thu, Feb 12, 2015 at 6:13 AM, Steven D'Aprano <steve at pearwood.info>
wrote:

> I certainly wouldn't want to write
>
>     new_dict = a + b + c + d
>
> and have O(N**2) performance when I can do this instead
>

It would likely not be O(N), but O(N**2) seems exaggerated. Besides, the
most common cases would be:


    new_dict = a + b
    old_dict += a

Both of which can be had in O(N).


>
>     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)

If that was so, then '+' could perhaps be implemented in terms of update()
with the help of some smarts from the parser.

Cheers,

-- 
Juancarlo *Añez*
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