### another way (but again *not the only way*) to do it ###

from contextlib import contextmanager

@contextmanager
def session_scope():
    """Provide a transactional scope around a series of operations."""
    session = Session()
    try:
        yield session
        session.commit()
    except:
        session.rollback()
        raise
    finally:
        session.close()


#all session.add will be done in session_scope(). tbd: remove individual commits from ORM_test.py
def run_my_program():
    with session_scope() as session:
        pass
        #ThingOne().go(session)
        #ThingTwo().go(session)