def _calc_purge_before(self):
        """Calculates time after which manifests should be purged."""
        
        if self.args.purge_before:
            return dt_util.parse_date_input(self.args.purge_before)
        
        assert 0 > (self.args.keep_days or -1)
        return dt_util.now() - datetime.timedelta(self.args.keep_days)
dataset/ETHPy150Open amorton/cassback/cassback/subcommands/purge_subcommand.py/PurgeSubCommand._calc_purge_before/swapped operands of `>`