Class ExtraAdder

src/structlog/stdlib.py:885–942

Add extra attributes of `logging.LogRecord` objects to the event dictionary. This processor can be used for adding data passed in the ``extra`` parameter of the `logging` module's log methods to the event dictionary. Args: allow: An optional collection of a

class ExtraAdder:
    """
    Add extra attributes of `logging.LogRecord` objects to the event
    dictionary.

    This processor can be used for adding data passed in the ``extra``
    parameter of the `logging` module's log methods to the event dictionary.

    Args:
        allow:
            An optional collection of attributes that, if present in
            `logging.LogRecord` objects, will be copied to event dictionaries.

            If ``allow`` is None all attributes of `logging.LogRecord` objects
            that do not exist on a standard `logging.LogRecord` object will be
            copied to event dictionaries.

    .. versionadded:: 21.5.0
    """

    __slots__ = ("_copier",)

    def __init__(self, allow: Collection[str] | None = None) -> None:
        self._copier: Callable[[EventDict, logging.LogRecord], None]
        if allow is not None:
            # The contents of allow is copied to a new list so that changes to
            # the list passed into the constructor does not change the
            # behaviour of this processor.
            self._copier = functools.partial(self._copy_allowed, [*allow])
        else:
            self._copier = self._copy_all

    def __call__(
        self, logger: logging.Logger, name: str, event_dict: EventDict
    ) -> EventDict:
        record: logging.LogRecord | None = event_dict.get("_record")
        if record is not None:
            self._copier(event_dict, record)
        return event_dict

    @classmethod
    def _copy_all(
        cls, event_dict: EventDict, record: logging.LogRecord
    ) -> None:
        for key, value in record.__dict__.items():
            if key not in _LOG_RECORD_KEYS:
                event_dict[key] = value

    @classmethod
    def _copy_allowed(
        cls,
        allow: Collection[str],
        event_dict: EventDict,
        record: logging.LogRecord,
    ) -> None:
        for key in allow:
            if key in record.__dict__:
                event_dict[key] = record.__dict__[key]