PEP 308: Pep Update

[Sheila King]

On Thu, 27 Feb 2003 19:10:06 +0100, "Anders J. Munch"
<andersjm at dancontrol.dk> wrote in comp.lang.python in article
<3e5e5441$0$16156$edfadb0f at dread11.news.tele.dk>:

> Yes.  And that makes list comprehensions the most confusing Python
> construct there is.  Not only doesn't it read left to right, it
> doesn't even read right to left either.
> 
> Until I tried it, I fully expected
> 
>     [x*y for x in (1,2) for y in (-1,+1)]
> 
> to produce
> 
>     [-1, -2, 1, 2]

I really do love the list comprehensions, myself. They are handy for a lot
of the email header and filtering type of scripts that I write.

I didn't find the example you posted confusing at all. It's just a nested
for-loop.

>>> [x*y for x in (1,2) for y in (-1,+1)]
[-1, 1, -2, 2]
>>> mylist = []
>>> for x in (1,2):
		for y in (-1, +1):
			mylist.append(x*y)

		
>>> mylist
[-1, 1, -2, 2]
>>> 




-- 
Sheila King
http://www.thinkspot.net/sheila/
http://www.k12groups.org/