Method open_resource

src/flask/app.py:330–361

Open a resource file relative to :attr:`root_path` for reading. For example, if the file ``schema.sql`` is next to the file ``app.py`` where the ``Flask`` app is defined, it can be opened with: .. code-block:: python with app.open_resource("schema.sql")

(
        self, resource: str, mode: str = "rb", encoding: str | None = None
    )

        )

    def open_resource(
        self, resource: str, mode: str = "rb", encoding: str | None = None
    ) -> t.IO[t.AnyStr]:
        """Open a resource file relative to :attr:`root_path` for reading.

        For example, if the file ``schema.sql`` is next to the file
        ``app.py`` where the ``Flask`` app is defined, it can be opened
        with:

        .. code-block:: python

            with app.open_resource("schema.sql") as f:
                conn.executescript(f.read())

        :param resource: Path to the resource relative to :attr:`root_path`.
        :param mode: Open the file in this mode. Only reading is supported,
            valid values are ``"r"`` (or ``"rt"``) and ``"rb"``.
        :param encoding: Open the file with this encoding when opening in text
            mode. This is ignored when opening in binary mode.

        .. versionchanged:: 3.1
            Added the ``encoding`` parameter.
        """
        if mode not in {"r", "rt", "rb"}:
            raise ValueError("Resources can only be opened for reading.")

        path = os.path.join(self.root_path, resource)

        if mode == "rb":
            return open(path, mode)  # pyright: ignore

        return open(path, mode, encoding=encoding)

    def open_instance_resource(
        self, resource: str, mode: str = "rb", encoding: str | None = "utf-8"