How to supress "Type doesn't have expected attributes"

So I have this method which creates an instance of a class.

    def process_item(self, json_item, msg_type):
        """
        Creates an item instance with the 'json_item' from the redis queue.
        Then the instance is used to create and send the alarm and ping request.
        At the end, the instance is deleted.
        :param msg_type: Type of message (Alarm or ping)
        :param json_item: The item from the redis queue in json format
        :return: None
        """
        item = Item(json_item)  # Creates an item instance with the json data.
        if msg_type == 'alarm':
            self.create_alarm_request(item)  # Here appears the warning
        elif msg_type == 'ping':
            self.create_ping_request(item)  # Here appears the warning
        else:
            self.logger.error("Unexpected error")
        del item

import json


class Item(object):

    def __init__(self, item):
        """
        Generates the object attributes from the json item in the arguments.
        The key is used as attribute name and value as attribute value
        :param item: Item in json format from redis queue
        """
        self.__dict__ = json.loads(item)

Type "Item" doesn't have expected attributes