[Python-ideas] Generator syntax hooks?

[Soni L.]

On 2017-08-07 08:35 PM, Steven D'Aprano wrote:
> Hi Soni, and welcome!
>
> On Mon, Aug 07, 2017 at 04:30:05PM -0300, Soni L. wrote:
>
>> What if, (x for x in integers if 1000 <= x < 1000000), was syntax sugar
>> for (x for x in range(1000, 1000000))?
> If you want the integers from 1000 to 1000000, use:
>
> range(1000, 1000000)
>
> Don't waste your time slowing down the code with an unnecessary and
> pointless wrapper that does nothing but pass every value on unchanged:
>
> (x for x in range(1000, 1000000))  # waste of time and effort
>
>
>

Actually, those have different semantics!

 >>> x = range(1, 10)
 >>> list(x)
[1, 2, 3, 4, 5, 6, 7, 8, 9]
 >>> list(x)
[1, 2, 3, 4, 5, 6, 7, 8, 9]

 >>> x = (x for x in range(1, 10))
 >>> list(x)
[1, 2, 3, 4, 5, 6, 7, 8, 9]
 >>> list(x)
[]