[Python-ideas] Namespace creation with syntax short form

[Peter Otten]

Steven D'Aprano wrote:

> On Fri, Feb 13, 2015 at 02:20:48PM +0100, Peter Otten wrote:
> 
>> a:1, b:2, c:3
>> 
>> has to create an object with three attributes "a", "b", and "c" and
> 
> This is ambiguous. Is it one object with three attributes, or a tuple of
> three namespace objects, each with one attribute?
> 
>  
>> :a, :b, :c = x
>> 
>> works on any x with three attributes "a", "b", and "c".
>> Implementationwise
> 
> I don't like the way that the colon jumps around from after the name to
> before the name. I don't like the way attributes are sometimes written
> with a dot and sometimes a colon:
> 
> x = a:1, b:2
> process(x.a)
> process(x:b)  # oops.
> 
> 
> I think it is awfully mysterious syntax and beginners are going to have
> a terrible time working out when they should use dot and when they
> should use colon.

I regret that I let Andrew lure me into a discussion of those details so 
soon. 

The point of my original answer was that if an acceptable syntax can be 
found real code can profit from it.

Personally, I would be OK with limiting this construct to return statements 
and the lhs of an assignment, but I doubt that this will gather the 
necessary support.