Method serialize

src/marshmallow/fields.py:314–340

Pulls the value for the given key from the object, applies the field's formatting and returns the result. :param attr: The attribute/key to get from the object. :param obj: The object to access the attribute/key from. :param accessor: Function used to access values f

(
        self,
        attr: str,
        obj: typing.Any,
        accessor: (
            typing.Callable[[typing.Any, str, typing.Any], typing.Any] | None
        ) = None,
        **kwargs,
    )

            raise self.make_error("null")

    def serialize(
        self,
        attr: str,
        obj: typing.Any,
        accessor: (
            typing.Callable[[typing.Any, str, typing.Any], typing.Any] | None
        ) = None,
        **kwargs,
    ):
        """Pulls the value for the given key from the object, applies the
        field's formatting and returns the result.

        :param attr: The attribute/key to get from the object.
        :param obj: The object to access the attribute/key from.
        :param accessor: Function used to access values from ``obj``.
        :param kwargs: Field-specific keyword arguments.
        """
        if self._CHECK_ATTRIBUTE:
            value = self.get_value(obj, attr, accessor=accessor)
            if value is missing_:
                default = self.dump_default
                value = default() if callable(default) else default
            if value is missing_:
                return value
        else:
            value = None
        return self._serialize(value, attr, obj, **kwargs)

    # If value is None, None may be returned
    @typing.overload