[Python-ideas] Fwd: unpacking generalisations for list comprehension

[Steven D'Aprano]

On Sat, Oct 15, 2016 at 05:38:15PM +0000, Neil Girdhar wrote:

> In ast.c, you can find:
> 
>                 if (is_dict) {
>                     ast_error(c, n, "dict unpacking cannot be used in "
>                             "dict comprehension");
>                     return NULL;
>                 }
>                 res = ast_for_dictcomp(c, ch);

[...]

Thanks for the pointer.


> > In any case, it isn't really the difficulty of implementation that
> > is being questioned. Many things are easy to implement, but we still
> > don't do them.
> 
> If it doesn't matter, why bring it up?

I never said it doesn't matter.

I brought it up because I'm curious. Because if it turns out that it 
actually is *difficult* to implement, that would be a point in my favour 
that *t doesn't naturally apply in list comps. And on the other hand, if 
it is *easy* to implement, that's a hint that perhaps I'm missing 
something and there is some natural interpretation of *t in a list comp 
that I've missed. Perhaps.

Just because I have a strong opinion doesn't mean I'm not willing to 
consider the possibility that I'm wrong.



-- 
Steve