List comprehension...

[Magnus L. Hetland]

Greg Ewing <greg.ewing at compaq.com> writes:

> "Magnus L. Hetland" wrote:
> > 
> >   [(i, s) for i in nums and s in strs]
> 
> That would be ambiguous, because it could be parsed as
> 
>    [(i, s) for i in (nums and s in strs)]

Which, in the case that nums is not an empty list, would be

     [(i, s) for i in nums]

IC. Oh, well... But what about:

     [(i, s) for i in nums, and s in strs]

This is still grammatically correct English, AFAIK...  And the ", and"
constellation does not have another valid interpretation, does it?

(Though it might not be really pretty...)

> 
> It *might* be feasible to use
> 
>    [(i, s) for i in nums and for s in strs]

Nice. Much less confusing than just using the *for* directly.

(Of course, any mechanisms of parallel iteration might be used here if
they appear... Like [(i, s) for i, s in nums, strs] or something)

> If I get a spare moment or two one day I'll try this
> and see whether the parser chokes. (Python's parser
> is a bit strange - it's hard to predict what it can
> handle and what it can't.)

Good :)

> 
> Greg

--

  Magnus          Echelon jamming noise:
  Lie             FBI CIA NSA Handgun Assault Bomb Drug Terrorism
  Hetland         Special Forces Delta Force AK47 Hillary Clinton