Remove index of a given set of data

def unindex(self, data, field):
        '''Remove index of a given set of data'''
        indices = extractIndices(self.index_fields[field])

        for doc in data:
            if doc:
                for _, index, preprocess in indices:
                    index.unindex(preprocess(doc))

        for index_type, index, _ in indices:

            index._index.initSearch()

            for predicate in self.index_fields[field][index_type]:
                logger.debug("Canopy: %s", str(predicate))
                predicate.index = index