docs: def list_devices(self, shop_id=None, page_index=1, page_size=20):
          """
          查询设备
  
          详情请参考
          http://mp.weixin.qq.com/wiki/10/6232005bdc497f7cf8e19d4e843c70d2.html
  
          :param shop_id: 可选，门店 ID
          :param page_index: 可选，分页下标，默认从1开始
          :param page_size: 可选，每页的个数，默认20个，最大20个
          :return: 返回的 JSON 数据包
          """
          data = optionaldict(
              shop_id=shop_id,
              pageindex=page_index,
              pagesize=page_size
          )
          res = self._post(
              'device/list',
              data=data,
              result_processor=lambda x: x['data']
          )
          return res