Method aggregate

pymongo/synchronous/database.py:639–720

Perform a database-level aggregation. See the `aggregation pipeline`_ documentation for a list of stages that are supported. .. code-block:: python # Lists all operations currently running on the server. with client.admin.aggregate([{"$currentOp": {}}

(
        self, pipeline: _Pipeline, session: Optional[ClientSession] = None, **kwargs: Any
    )

            return coll

    def aggregate(
        self, pipeline: _Pipeline, session: Optional[ClientSession] = None, **kwargs: Any
    ) -> CommandCursor[_DocumentType]:
        """Perform a database-level aggregation.

        See the `aggregation pipeline`_ documentation for a list of stages
        that are supported.

        .. code-block:: python

           # Lists all operations currently running on the server.
           with client.admin.aggregate([{"$currentOp": {}}]) as cursor:
               for operation in cursor:
                   print(operation)

        The :meth:`aggregate` method obeys the :attr:`read_preference` of this
        :class:`Database`, except when ``$out`` or ``$merge`` are used, in
        which case  :attr:`~pymongo.read_preferences.ReadPreference.PRIMARY`
        is used.

        Cursors are closed automatically when they are exhausted (the last batch of data is retrieved from the database).
        If a cursor is not exhausted, it will be closed automatically upon garbage collection, which leaves resources open but unused for a potentially long period of time.
        To avoid this, best practice is to call :meth:`Cursor.close` when the cursor is no longer needed,
        or use the cursor in a with statement.

        .. note:: This method does not support the 'explain' option. Please
           use :meth:`~pymongo.database.Database.command` instead.

        .. note:: The :attr:`~pymongo.database.Database.write_concern` of
           this collection is automatically applied to this operation.

        :param pipeline: a list of aggregation pipeline stages
        :param session: a
            :class:`~pymongo.client_session.ClientSession`.
        :param kwargs: extra `aggregate command`_ parameters.

        All optional `aggregate command`_ parameters should be passed as
        keyword arguments to this method. Valid options include, but are not
        limited to:

          - `allowDiskUse` (bool): Enables writing to temporary files. When set
            to True, aggregation stages can write data to the _tmp subdirectory
            of the --dbpath directory. The default is False.
          - `maxTimeMS` (int): The maximum amount of time to allow the operation
            to run in milliseconds.
          - `batchSize` (int): The maximum number of documents to return per
            batch. Ignored if the connected mongod or mongos does not support
            returning aggregate results using a cursor.
          - `collation` (optional): An instance of
            :class:`~pymongo.collation.Collation`.
          - `let` (dict): A dict of parameter names and values. Values must be
            constant or closed expressions that do not reference document
            fields. Parameters can then be accessed as variables in an
            aggregate expression context (e.g. ``"$$var"``). This option is
            only supported on MongoDB >= 5.0.

        :return: A :class:`~pymongo.command_cursor.CommandCursor` over the result
          set.