python使用protobufde的过程解析

syntax = "proto3";

package  WeightEstimationUpdate;
option   java_package = "com.muyuan.platform.bar.patrol.pro";
// 请求包基类（没有附加数据，通信包不重新定义直接使用基类包）
message BaseRequestCommon
{
  string      DeviceId = 1;    // 设备编号
  string      MsgID = 2;    // 消息ID,用UUID
  string      Timestamp = 3;    // unix时间戳(秒)
  uint32      Cmd = 4;    // 指令信息
  bytes       payLoad = 5;  // 消息体
}

// 上报
message DeviceRegist
{
  string  version = 1;    // 
  string  macAddr = 2;    // 
}

// 下发
message PushUpgradeInfo
{
  string  version = 1;            // 版本号
  string  packageName = 2;          // 
  string  packageMd5 = 3;          // 
  string  packageUrl = 4;          // 
}

// 上报
message ReportWeightEstimationStatus
{
  string      version = 1;    // 
  string      state = 2;      // 
}

// 指令列表
enum EmCmd
{
  CMD_NONE = 0x0000;       // 指令开始范围

  //-----------------服务器端主动下发到设备端信令定义开始------------------
  CMD_S2C_PUSH_UPGRADE_INFO = 0x0013;    // 下发（协议包：PushUpgradeInfo）
  //-----------------服务器端主动下发到设备端信令定义结束-----------------

  //-----------------设备端主动上报到服务端信令定义开始-------------------
  CMD_C2S_REPORT_REGIST = 0x0060;   // 注册（协议包：WeightEstimationRegist）
  CMD_C2S_REPORT_FAULT = 0x0061;   // 上报故障（协议包：ReportFault）
  CMD_C2S_REPORT_WEIGHT_ESTIMATION_STATUS = 0x0063;    // 上报状态信息（协议包：WeightEstimationStatus）
  //-----------------设备端主动上报到服务端信令定义结束-----------------

  CMD_END = 0xFFFF;        // 指令结束范围
}

import test_pb2 as weight_pd
base_request_common_obj = weight_pd.BaseRequestCommon()
base_request_common_obj.ParseFromString(msg)
payload = base_request_common_obj.payLoad
push_upgrade_info_obj = weight_pd.PushUpgradeInfo()
push_upgrade_info_obj.ParseFromString(payload)
update_version = push_upgrade_info_obj.version
update_zip_filename = push_upgrade_info_obj.packageName
# 反向解析即可

import test_pb2 as weight_pd
base_request_common = weight_pd.BaseRequestCommon()
base_request_common.DeviceId = deviceId
base_request_common.MsgID = str(uuid.uuid4())
base_request_common.Timestamp = str(int(time.time()))
# change
item_list = weight_pd.EmCmd.items()
#此为 protobuf 3.0.0 版本的
weight_dict = listtuple_dict(item_list)
base_request_common.Cmd = weight_dict.get("CMD_C2S_REPORT_WEIGHT_ESTIMATION_STATUS")
#此为 protobuf 最新版本  
# base_request_common.Cmd = weight_pd.EmCmd.CMD_C2S_REPORT_WEIGHT_ESTIMATION_STATUS
report_weight_estimation_status = weight_pd.ReportWeightEstimationStatus()
report_weight_estimation_status.version = self.version
report_weight_estimation_status.state = state
base_request_common.payLoad = report_weight_estimation_status.SerializeToString()
serializeToString = base_request_common.SerializeToString()
#  serializeToString 即为 二进制数据流
def listtuple_dict(item_list):
    weight_cmd_dict = {}
    for k, v in item_list:
        weight_cmd_dict.setdefault(k, v)
    return weight_cmd_dict```