Fwd: Re: [Zope] Search a Catalog in Python

14 Mar 2004

      -----Original Message-----
From: "Richard Jennings" <rjennings@stradefi.com>
To: Andreas Jung <andreas@andreas-jung.com>
Date: Sun, 14 Mar 2004 10:48:28 +0100
Subject: Re: [Zope] Search a Catalog in Python

On Sunday 14 March 2004 08:48, Andreas Jung wrote:
...
If there is something going wrtong than you should provide error
messages
and tracebacks.
The only thing I see is the use of the search() method instead of
searchResults().
-aj
--On Samstag, 13. März 2004 19:12 Uhr +0100 Andre Meyer <meyer@acm.org>
wrote:
...
Dear Zopers
...
...
This time, I thought it should be simple, but I am struggling again:
The idea was to search for items that have been catalogued
successfully.
In the Zope Book they describe how to do this using form and scripts.
That works for me, too, but then I need to search in a regular Python
program (An FS product).
For this purpose, I found the ZCatalog.search method and gave it a
try,
but I cannot get it to work. It expects a dictionary, but what does
that
contain?
Here is what I have so far:
__init__(self, id, title, ...):
     ...
      # add a Catalog
      _catalog = ZCatalog('Catalog')
            # add Metadata fields for the Catalog
      _catalog.addColumn('id')
      _catalog.addColumn('title')
      _catalog.addColumn('icon')
# PathIndex
      _catalog.addIndex('path_index', 'PathIndex')
# ZCTextIndex (with the required Lexicon)
      class Extra:
          """ Just a dummy to build records for the Lexicon.
          """
          pass
      extra = Extra()
      extra.index_type = 'Okapi BM25 Rank'
      extra.lexicon_id = 'Lexicon'
      _catalog._setObject('Lexicon', PLexicon('Lexicon', '',
Splitter(),
CaseNormalizer()))
      _catalog.addIndex('title', 'ZCTextIndex', extra)
# FieldIndex
      _catalog.addIndex('composer_first_name_index', 'FieldIndex',
'first_name')
      _catalog.addIndex('composer_last_name_index', 'FieldIndex',
'last_name')
      _catalog.addIndex('composer_year_of_birth_index', 'FieldIndex',
'year_of_birth')
self._setObject('Catalog', _catalog)
...
# all new items get catalogued (verified) and now
      # we should be able to search for them like this:
      def searchForAnItem(item)
          obj=self.Catalog.search(last_name_index={'query': ['Aaa']})
Hi,

wouldn't presume to offer help, but I can show you what works for me:

I have catalog, 'processRoles', containing several different field
indexes to process
role objects.  To get the catalog entry for a specific role I do:

result = self.processRoles({'entityId':roleId}) where roleId is index
value.

the result is 'None', an object or a list of objects having the index. 
These objects
are 'mybrains' instances which behave like dictionaries with additional
methods. HTH.

<rant disclaimer='this is NOT aimed at anyone, just the
state-of-the-art'>
I work almost entirely with products and face the same lack of examples
working with
python. Casey Duncan seems to be the catalog guru and if he reads this
perhaps he
could point us poor mortals in the direction of some (any?) documentation
which gives
python programming introduction to catalog & ZCatalog. For me, trying to
deduce the
functionality of catalog from the source is like trying to deduce the
appearance of a
pyramid from a 1 ton block of sand stone.
</rant>

Richard Jennings
--------------------------
'Just a bloke doing a job he (mostly) enjoys'