def _get_instance_hours(self, exist):
        if (exist.deleted_at is None) or (exist.deleted_at > exist.audit_period_ending):
            end = exist.audit_period_ending
        else:
            end = exist.deleted_at
        if exist.audit_period_beginning > exist.launched_at:
            start = exist.launched_at
        else:
            start = exist.audit_period_beginning
        return math.ceil((end - start)/3600)
dataset/ETHPy150Open openstack/stacktach/reports/instance_hours.py/InstanceHoursReport._get_instance_hours/swapped operands of `>`