Gwildor

@event.listens_for(Session, 'after_begin')
def session_after_begin(session, transaction, connection):
    session.info['clean'] = True


@event.listens_for(Session, 'after_flush')
def session_after_flush(session, flush_context):
    if session.new or session.dirty or session.deleted:
        session.info['clean'] = False