Method open_session

src/flask/sessions.py:249–261

This is called at the beginning of each request, after pushing the request context, before matching the URL. This must return an object which implements a dictionary-like interface as well as the :class:`SessionMixin` interface. This will return ``None`` to indicate

(self, app: Flask, request: Request)

        )

    def open_session(self, app: Flask, request: Request) -> SessionMixin | None:
        """This is called at the beginning of each request, after
        pushing the request context, before matching the URL.

        This must return an object which implements a dictionary-like
        interface as well as the :class:`SessionMixin` interface.

        This will return ``None`` to indicate that loading failed in
        some way that is not immediately an error. The request
        context will fall back to using :meth:`make_null_session`
        in this case.
        """
        raise NotImplementedError()

    def save_session(
        self, app: Flask, session: SessionMixin, response: Response