Method get_version

gridfs/asynchronous/grid_file.py:178–235

Get a file from GridFS by ``"filename"`` or metadata fields. Returns a version of the file in GridFS whose filename matches `filename` and whose metadata fields match the supplied keyword arguments, as an instance of :class:`~gridfs.grid_file.GridOut`. Version numbe

(
        self,
        filename: Optional[str] = None,
        version: Optional[int] = -1,
        session: Optional[AsyncClientSession] = None,
        **kwargs: Any,
    )

        return gout

    async def get_version(
        self,
        filename: Optional[str] = None,
        version: Optional[int] = -1,
        session: Optional[AsyncClientSession] = None,
        **kwargs: Any,
    ) -> AsyncGridOut:
        """Get a file from GridFS by ``"filename"`` or metadata fields.

        Returns a version of the file in GridFS whose filename matches
        `filename` and whose metadata fields match the supplied keyword
        arguments, as an instance of :class:`~gridfs.grid_file.GridOut`.

        Version numbering is a convenience atop the GridFS API provided
        by MongoDB. If more than one file matches the query (either by
        `filename` alone, by metadata fields, or by a combination of
        both), then version ``-1`` will be the most recently uploaded
        matching file, ``-2`` the second most recently
        uploaded, etc. Version ``0`` will be the first version
        uploaded, ``1`` the second version, etc. So if three versions
        have been uploaded, then version ``0`` is the same as version
        ``-3``, version ``1`` is the same as version ``-2``, and
        version ``2`` is the same as version ``-1``.

        Raises :class:`~gridfs.errors.NoFile` if no such version of
        that file exists.

        :param filename: ``"filename"`` of the file to get, or `None`
        :param version: version of the file to get (defaults
            to -1, the most recent version uploaded)
        :param session: a
            :class:`~pymongo.client_session.AsyncClientSession`
        :param kwargs: find files by custom metadata.

        .. versionchanged:: 3.6
           Added ``session`` parameter.

        .. versionchanged:: 3.1
           ``get_version`` no longer ensures indexes.
        """
        query = kwargs
        if filename is not None:
            query["filename"] = filename

        _disallow_transactions(session)
        cursor = self._files.find(query, session=session)
        if version is None:
            version = -1
        if version < 0:
            skip = abs(version) - 1
            cursor.limit(-1).skip(skip).sort("uploadDate", DESCENDING)
        else:
            cursor.limit(-1).skip(version).sort("uploadDate", ASCENDING)
        try:
            doc = await anext(cursor)
            return AsyncGridOut(self._collection, file_document=doc, session=session)
        except StopAsyncIteration:
            raise NoFile("no version %d for filename %r" % (version, filename)) from None