Normalize catalog keywords

normalize.py

# -*- coding: utf-8 -*-
from plone import api

import transaction


def normalize():
    """Remove spare spaces and transform keywords to lowercase."""
    catalog = api.portal.get_tool('portal_catalog')
    results = catalog()
    n = 0
    for i, b in enumerate(results, 1):
        try:
            obj = b.getObject()
        except (AttributeError, KeyError):
            continue  # skip broken objects
        keywords = list(obj.Subject())
        # remove spare spaces
        normalized = [' '.join(k.split()) for k in keywords if k]
        # transform to lower case
        lowercase = [k.lower() for k in normalized]
        if keywords == lowercase:
            continue  # no changes on object
        obj.setSubject(tuple(lowercase))
        catalog.catalog_object(obj, idxs=['Subject'], update_metadata=False)
        n += 1
        if n % 1000 == 0:
            transaction.savepoint()
    transaction.commit()