def _deserialize(self, value, attr, data):
        """Deserialize an ISO8601-formatted date string to a
        :class:`datetime.date` object.
        """
        if not value:  # falsy values are invalid
            self.fail('invalid')
        try:
            return utils.from_iso_date(value)
        except (AttributeError, TypeError, __HOLE__):
            self.fail('invalid')
dataset/ETHPy150Open marshmallow-code/marshmallow/marshmallow/fields.py/Date._deserialize