@event.listens_for(Event, 'after_insert')
def create_version_info(mapper, conn, target):
 version = Version(event_id=target.id)
 target.version = version

@ event . listens_for ( Event , 'after_insert' ) def create_version_info ( mapper , conn , target ) : version = Version ( event_id = target . id ) target . version = version
create version instance after event created .