Proposed new syntax

[Wolfgang Maier]

On 08/10/2017 04:28 PM, Steve D'Aprano wrote:
> Every few years, the following syntax comes up for discussion, with some people
> saying it isn't obvious what it would do, and others disagreeing and saying
> that it is obvious. So I thought I'd do an informal survey.
> 
> What would you expect this syntax to return?

As one of the people who have suggested this or similar syntax once I 
hope I'm not too far off a potential consensus :)

> 
> [x + 1 for x in (0, 1, 2, 999, 3, 4) while x < 5]
> 

[1, 2, 3]

> 
> For comparison, what would you expect this to return? (Without actually trying
> it, thank you.)
> 
> [x + 1 for x in (0, 1, 2, 999, 3, 4) if x < 5]
> 

[1, 2, 3, 4, 5]

> 
> How about these?
> 
> [x + y for x in (0, 1, 2, 999, 3, 4) while x < 5 for y in (100, 200)]
> 

[100, 200, 101, 201, 102, 202]

> [x + y for x in (0, 1, 2, 999, 3, 4) if x < 5 for y in (100, 200)]
> 

[100, 200, 101, 201, 102, 202, 103, 203, 104, 204]

> 
> Thanks for your comments!
> 
> 
>