On 4/12/06, Max Battcher <[EMAIL PROTECTED]> wrote: > Oh, right. You could do: > > tags = [tag for tag in Tag.objects.all() if tag.article_set.count() == 0] > > n queries for n tags, but it is "pretty" Python. Doing db-cleanup > shouldn't happen all that often, so you probably don't need the best > performance, and I'd just stick with the list comprehension. > > Too bad there isn't some cool easy Python way to make a list > comprehension/generators like that as Lazy as the Descriptors...
There is, but it's only in Python 2.4: >>> g = (x**2 for x in range(10)) >>> g <generator object at 0xb7d711cc> >>> g.next() 0 >>> g.next() 1 >>> g.next() 4 Check out http://www.python.org/dev/peps/pep-0289/ (Generator Expressions) -- Ian Clelland <[EMAIL PROTECTED]> --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~----------~----~----~----~------~----~------~--~---
