def last_update(self):
        """
            Get the last update meta-data of the current record

            @return: a dict {modified_by: <user>, modified_on: <datestr>},
                     depending on which of these attributes are available
                     in the current record
        """

        output = {}
        record_id = self.record_id
        if record_id:
            record = None
            fields = []
            table = self.table
            if "modified_on" in table.fields:
                fields.append(table.modified_on)
            if "modified_by" in table.fields:
                fields.append(table.modified_by)

            if fields:
                query = (table._id == record_id)
                record = current.db(query).select(limitby=(0, 1),
                                                  *fields).first()
            if record:
                T = current.T
                if "modified_by" in record:
                    if not record.modified_by:
                        modified_by = T("anonymous user")
                    else:
                        modified_by = \
                            table.modified_by.represent(record.modified_by)
                    output["modified_by"] = T("by %(person)s") % \
                                             {"person": modified_by}
                if "modified_on" in record:
                    modified_on = \
                        S3DateTime.datetime_represent(record.modified_on,
                                                      utc=True,
                                                      )
                    output["modified_on"] = T("on %(date)s") % \
                                             {"date": modified_on}
        return output

    # -------------------------------------------------------------------------
dataset/ETHPy150Open sahana/eden/modules/s3/s3crud.py/S3CRUD.last_update/original