# [Python-Dev] Features for Python 2.0

**Moshe Zadka
**
Moshe Zadka <moshez@math.huji.ac.il>

*Tue, 25 Jul 2000 16:30:16 +0300 (IDT)*

On Tue, 25 Jul 2000, Guido van Rossum wrote:
>* > List comprehensions' problems is that we cannot find a syntax that we all
*>* > agree is readable. Perhaps the answer is not list comprehensions, but
*>* > lexical scoping combined with steroid versions of map and filter, together
*>* > with zip to bind things together.
*>*
*>* I'm about 3000 messages behind in that particular discussion. I still
*>* really like Greg Ewing's original syntax:
*>*
*>* [x for x in seq]
*
I think the main problem with this syntax was that there is no seperator
between the expression and the "for". Not a parser issue, but a human one:
the same reason there is a colon after the "if" keyword.
Now,
[x; for x in seq]
and
[x: for x in seq]
each had their objections. These will all probably be in the PEP, so
I'll shut up now.
>* [x+y for x in seq1 for y in seq2]
*>* [x for x in seq if pred(x)]
*>* [x, x*2 for x in seq]
*
And what about
[x+y for x in seq1 for y in seq2 if y>2 if x<3]
or
[x+y for x in seq1 if x<3 for y in seq2 if y>2]
What is allowed? Aren't we being a bit too TIMTOWTDIish here?
(From there on, the discussion diverged)
--
Moshe Zadka <moshez@math.huji.ac.il>
There is no IGLU cabal.
http://advogato.org/person/moshez