[Zope] getting the number of returned objects

[Chris McDonough]

Oh OK. As long as you know it's not advised, try this:

<dtml-var "_.len(getResults())">

----- Original Message -----
From: "Timothy Wilson" <wilson@visi.com>
To: "Zope listserv" <zope@zope.org>
Sent: Saturday, October 20, 2001 3:25 PM
Subject: Re: [Zope] getting the number of returned objects


> On Sat, 20 Oct 2001, Chris McDonough wrote:
>
> > Getting the number of results returned by a Catalog query is a thing
> > that folks commonly want to do, and usually just doing len(resultset)
> > works OK.  I'm surprised it didn't for you.
> >
> > That said, it's an extremely expensive operation under some
> > circumstances because it un-lazifies the carefully-lazified Catalog
> > resultset, creating a brain object for each matching catalog record.  If
> > there's a way to not do this in your application, I'd recommend it.
>
> Thanks for the quick reply. The cost of this particular operation isn't
> really important since this method will only get called once per day. (I'm
> trying to set up a method that will email the next day's school lunch
menus
> to a listserv *if* there is a lunch menu for tomorrow.)
>
> I know it works to make two scripts, the first Python Script simply does
the
> Catalog query and returns true if the query returned anything, and the
> second DTML Method just does the query again if the result of calling the
> first Python Script was "true" and processes the results.
>
> -Tim
>
> --
> Tim Wilson      |   Visit Sibley online:   | Check out:
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> W. St. Paul, MN |                          | http://slashdot.org
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>
>
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