Class Primary

pymongo/read_preferences.py:280–305

Primary read preference. * When directly connected to one mongod queries are allowed if the server is standalone or a replica set primary. * When connected to a mongos queries are sent to the primary of a shard. * When connected to a replica set queries are sent to the primary of

class Primary(_ServerMode):
    """Primary read preference.

    * When directly connected to one mongod queries are allowed if the server
      is standalone or a replica set primary.
    * When connected to a mongos queries are sent to the primary of a shard.
    * When connected to a replica set queries are sent to the primary of
      the replica set.
    """

    __slots__ = ()

    def __init__(self) -> None:
        super().__init__(_PRIMARY)

    def __call__(self, selection: Selection) -> Selection:
        """Apply this read preference to a Selection."""
        return selection.primary_selection

    def __repr__(self) -> str:
        return "Primary()"

    def __eq__(self, other: Any) -> bool:
        if isinstance(other, _ServerMode):
            return other.mode == _PRIMARY
        return NotImplemented


class PrimaryPreferred(_ServerMode):