gistfile1.py

def get_session():
    session = was.orm.Session(bind=engine)
    flask.g.session = session
    flask.g.session_got = True
    return flask.g.session
    

@before_request
def define_session():
    flask.g.session = werkzeug.local.LocalProxy(get_session)


@teardown_request
def close_session():
    if hasattr(flask.g, 'session_got'):
        flask.g.session.close()