orm.py 文件源码

def __init__(self, url, **kwargs):
        """Initialises a database connection to a given database url.

        Parameters
        ----------
        url : url
            A sqlalchemy url to connect to a specified database.
        kwargs : dict
            Additional keys will be passed at create_engine.
        """
        super().__init__()

        self.url = url

        self.log.info("Creating session to db: {}".format(self.url))
        self.engine = create_engine(self.url, **kwargs)

        try:
            self.session_class = sessionmaker(bind=self.engine)
        except OperationalError:
            self.log.exception(
                "Failed to connect db session: {}".format(self.url)
            )
            raise