session.py 文件源码

def _login(self):
        name = os.environ.get("USER")
        if not name:
            raise ValueError("Missing environment variable 'USER'. FeatureHub"
                             " session not initialized.")

        with self.__orm.session_scope() as session:
            try:
                user = session.query(User)\
                              .filter(User.name == name)\
                              .one()
                self.__username = user.name
            except NoResultFound:
                data = { "database" : self.__orm.database }
                response = Session._eval_server_post("create-user", data)
                if response.ok:
                    self.__username = name
                else:
                    raise ValueError("Couldn't log in to FeatureHub. " \
                                     + TRY_AGAIN_LATER) 

            except MultipleResultsFound as e:
                raise ValueError("Unexpected error logging in to FeatureHub. " \
                                 + TRY_AGAIN_LATER)