Method get_expiration_time

src/flask/sessions.py:223–231

A helper method that returns an expiration date for the session or ``None`` if the session is linked to the browser session. The default implementation returns now + the permanent session lifetime configured on the application.

(self, app: Flask, session: SessionMixin)

        return app.config["SESSION_COOKIE_PARTITIONED"]  # type: ignore[no-any-return]

    def get_expiration_time(self, app: Flask, session: SessionMixin) -> datetime | None:
        """A helper method that returns an expiration date for the session
        or ``None`` if the session is linked to the browser session.  The
        default implementation returns now + the permanent session
        lifetime configured on the application.
        """
        if session.permanent:
            return datetime.now(timezone.utc) + app.permanent_session_lifetime
        return None

    def should_set_cookie(self, app: Flask, session: SessionMixin) -> bool:
        """Used by session backends to determine if a ``Set-Cookie`` header