On Fri, 26 Feb 2010 13:11:10 +1300 Greg Ewing <greg.ewing@canterbury.ac.nz> wrote:
Fred Drake wrote:
I like this, but it has the same readability issue I noted for cases where decomposition is used:
[(k, v) from somedict.items() if condition(v)]
I don't think that's too bad if you keep in mind that
[x from stuff]
is a shorthand for
[x for x in stuff]
whatever x happens to be. So your example would be equivalent to
[(k, v) for (k, v) in somedict.items() if condition(v)]
As a bonus, the short form could probably be made more efficient, because the tuples produced by the for-loop could be put straight into the result list, instead of having to re-pack k and v into a new tuple.
(Discussing my own shorthand proposal :-) Sure, but remains a lexical issue: [x in stuff] (x in stuff) cannot be accepted because of ambiguity with membership test in the iterator case. [x from stuff] (x from stuff)) solves that. But then for consistency "from" should be extented to all comprehensions [x*x for x from stuff if x%2==1] and, more importantly, to traversal loops: for x from stuff: because the sense is analog. "in" would remain only as membership test operator. This is very few probable ;-) The issue is the ambiguity of "in". Denis -- ________________________________ la vita e estrany spir.wikidot.com