persist.py 文件源码

def sqlalchemy_metadata(host, port, database, username, password):
    url = URL(drivername='postgresql+psycopg2', username=username,
              password=password, host=host, port=port, database=database)
    engine = create_engine(url, server_side_cursors=True, connect_args={'connect_timeout': 4})
    # ensure that we can connect
    with engine.begin():
        pass  # this will throw OperationalError if it fails
    return MetaData(engine)