def command(self, dbname, spec, slave_ok=False,
                read_preference=ReadPreference.PRIMARY,
                codec_options=DEFAULT_CODEC_OPTIONS, check=True,
                allowable_errors=None, check_keys=False,
                read_concern=None,
                write_concern=None,
                parse_write_concern_error=False,
                collation=None,
                session=None,
                client=None,
                retryable_write=False,
                publish_events=True,
                user_fields=None):
        """Execute a command or raise an error.

        :Parameters:
          - `dbname`: name of the database on which to run the command
          - `spec`: a command document as a dict, SON, or mapping object
          - `slave_ok`: whether to set the SlaveOkay wire protocol bit
          - `read_preference`: a read preference
          - `codec_options`: a CodecOptions instance
          - `check`: raise OperationFailure if there are errors
          - `allowable_errors`: errors to ignore if `check` is True
          - `check_keys`: if True, check `spec` for invalid keys
          - `read_concern`: The read concern for this command.
          - `write_concern`: The write concern for this command.
          - `parse_write_concern_error`: Whether to parse the
            ``writeConcernError`` field in the command response.
          - `collation`: The collation for this command.
          - `session`: optional ClientSession instance.
          - `client`: optional MongoClient for gossipping $clusterTime.
          - `retryable_write`: True if this command is a retryable write.
          - `publish_events`: Should we publish events for this command?
          - `user_fields` (optional): Response fields that should be decoded
            using the TypeDecoders from codec_options, passed to
            bson._decode_all_selective.
        """
        self.validate_session(client, session)
        session = _validate_session_write_concern(session, write_concern)

        # Ensure command name remains in first place.
        if not isinstance(spec, ORDERED_TYPES):
            spec = SON(spec)

        if (read_concern and self.max_wire_version < 4
                and not read_concern.ok_for_legacy):
            raise ConfigurationError(
                'read concern level of %s is not valid '
                'with a max wire version of %d.'
                % (read_concern.level, self.max_wire_version))
        if not (write_concern is None or write_concern.acknowledged or
                collation is None):
            raise ConfigurationError(
                'Collation is unsupported for unacknowledged writes.')
        if (self.max_wire_version >= 5 and
                write_concern and
                not write_concern.is_server_default):
            spec['writeConcern'] = write_concern.document
        elif self.max_wire_version < 5 and collation is not None:
            raise ConfigurationError(
                'Must be connected to MongoDB 3.4+ to use a collation.')

        if session:
            session._apply_to(spec, retryable_write, read_preference)
        self.send_cluster_time(spec, session, client)
        listeners = self.listeners if publish_events else None
        unacknowledged = write_concern and not write_concern.acknowledged
        if self.op_msg_enabled:
            self._raise_if_not_writable(unacknowledged)
        try:
            return command(self.sock, dbname, spec, slave_ok,
                           self.is_mongos, read_preference, codec_options,
                           session, client, check, allowable_errors,
                           self.address, check_keys, listeners,
                           self.max_bson_size, read_concern,
                           parse_write_concern_error=parse_write_concern_error,
                           collation=collation,
                           compression_ctx=self.compression_context,
                           use_op_msg=self.op_msg_enabled,
                           unacknowledged=unacknowledged,
                           user_fields=user_fields)
        except OperationFailure:
            raise
        # Catch socket.error, KeyboardInterrupt, etc. and close ourselves.
        except BaseException as error:
            self._raise_connection_failure(error)
Execute a command or raise an error.

        :Parameters:
          - `dbname`: name of the database on which to run the command
          - `spec`: a command document as a dict, SON, or mapping object
          - `slave_ok`: whether to set the SlaveOkay wire protocol bit
          - `read_preference`: a read preference
          - `codec_options`: a CodecOptions instance
          - `check`: raise OperationFailure if there are errors
          - `allowable_errors`: errors to ignore if `check` is True
          - `check_keys`: if True, check `spec` for invalid keys
          - `read_concern`: The read concern for this command.
          - `write_concern`: The write concern for this command.
          - `parse_write_concern_error`: Whether to parse the
            ``writeConcernError`` field in the command response.
          - `collation`: The collation for this command.
          - `session`: optional ClientSession instance.
          - `client`: optional MongoClient for gossipping $clusterTime.
          - `retryable_write`: True if this command is a retryable write.
          - `publish_events`: Should we publish events for this command?
          - `user_fields` (optional): Response fields that should be decoded
            using the TypeDecoders from codec_options, passed to
            bson._decode_all_selective.
        
stackoverflow/venv/lib/python3.6/site-packages/pymongo/pool.py