Python读取及生成pb文件，pb与jsonStr互转，pb与dictJson互转，打包.exe/.sh并转换，很完美跨平台

- 1. 效果图
- 2. 命令行：proto文件转.class（绝对路径或相对路径）
- 3. 序列化、反序列化api
- 4. pb转json，json转pb，pb转dict
- 5. 打包.exe/.sh并调用
- 6. 源代码
- - 6.1 addressbook.proto
  - 6.2 pb2json.py
- 参考

读取pb及生成pb文件
pb文件转jsonString
二进制pb转jsonString
二进制pb转jsonDict
jsonString转pb
jsonDict转pb
赋值（有空或者类型不对应会无法赋值及报错）
打包exe/sh

1. 效果图

读取pb文件并解析为jsonStr打印
在这里插入图片描述

2. 命令行：proto文件转.class（绝对路径或相对路径）

d:
cd D:\study\python-scripts\p20230731\pb2json
protoc -I=D:\study\python-scripts\p20230731\pb2json\ --python_out=D:\study\python-scripts\p20230731\pb2json\ D:\study\python-scripts\p20230731\pb2json\addressbook.proto

d:
cd D:\study\python-scripts\p20230731\pb2json
protoc -I=. --python_out=./ ./addressbook.proto

效果图如下：

在这里插入图片描述

执行成功后会在本地生成： addressbook_pb2.py
在这里插入图片描述
Java 和 Python不一致的地方，Java可以指定包名，类名（.proto名称可以随意）；会自适应生成相应的JavaPB对象
Python可以指定包名，不指定类名(.proto名称固定)，默认为 aaa.proto 则生成 aaa_pb2.py类

3. 序列化、反序列化api

IsInitialized()：检查是否已设置所有必填字段。
str()：返回消息的人类可读表示形式，对于调试特别有用。（通常调用为 str(message) 或 print message.）
CopyFrom(other_msg)：用给定消息的值。
Clear()：将所有元素清除回空状态。

协议缓冲区类有用于写入和读取消息的方法使用协议缓冲区的所选类型二进制格式。这些包括：

SerializeToString()：序列化消息并将其作为字符串返回。请注意，字节是二进制的，而不是文本的;我们只使用 str 键入为方便的容器。
ParseFromString(data)：从给定字符串解析消息

4. pb转json，json转pb，pb转dict

google.protobuf.json_format
https://googleapis.dev/python/protobuf/latest/google/protobuf/json_format.html

5. 打包.exe/.sh并调用

windows下到打包

pyinstaller pb2json.py

上边的语句可能会报错： Error loading Python DLL
‘C:\Users\ADMINI~1\AppData\Local\Temp_MEI41642\python310.dll’
LoadLibrary：找不到指定的模块。

用下边的语句ok：

pyinstaller --onefile pb2json.py

linux平台打包则得到可在linux平台运行的二进制可执行文件

6. 源代码

6.1 addressbook.proto

syntax = "proto3";

package tutorial;

message Person {
  string name = 1;
  int32 id = 2;
  string email = 3;

  enum PhoneType {
    PHONE_TYPE_UNSPECIFIED = 0;
    PHONE_TYPE_MOBILE = 1;
    PHONE_TYPE_HOME = 2;
    PHONE_TYPE_WORK = 3;
  }

  message PhoneNumber {
    string number = 1;
    PhoneType type = 2;
  }

  repeated PhoneNumber phones = 4;
}

message AddressBook {
  repeated Person people = 1;
}

6.2 pb2json.py

#!/usr/bin/env python3
import json
import sys

from google.protobuf import json_format

import addressbook_pb2

if len(sys.argv) == 2:
    print("Usage:", sys.argv[0], sys.argv[1], "address_file")
    print('--------------------------------------------------------')
    pb_path = sys.argv[1]
    address = addressbook_pb2.AddressBook()

    # 从已经存在的文件读取pb
    try:
        with open(pb_path, "rb") as f:
            address.ParseFromString(f.read())
    except IOError:
        print(pb_path + ": Could not open file...")

    # pb转json
    json_string = json_format.MessageToJson(address)
    print('json_string: ', json_string)
    print('--------------------------------------------------------')



address_book = addressbook_pb2.AddressBook()
# person = addressbook_pb2.Person() # 初始化方式1
person = address_book.people.add()  # 初始化方式2
person.id = 1234
person.name = "John Doe"
person.email = "jdoe@example.com"
phone = person.phones.add()
phone.number = "555-4321"
phone.type = addressbook_pb2.Person.PHONE_TYPE_HOME

person2 = address_book.people.add()  # 初始化方式2
person2.id = 1314
person2.name = "Lucy"
person2.email = "Lucy@example.com"
phone2 = person2.phones.add()
phone2.number = "010-4321"
phone2.type = addressbook_pb2.Person.PHONE_TYPE_WORK

# 请注意，这些赋值不仅仅是向 通用 Python 对象。如果要尝试分配未定义的字段 在 .proto 文件，一个 AttributeError 会被提出来。
# 如果分配字段 对于错误类型的值，a TypeError 将被提出。另外，阅读 字段在设置之前的值将返回默认值。
try:
    person.no_such_field = 1  # raises AttributeError
    person.id = "1234"  # raises TypeError
except AttributeError as e:
    print('AttributeError:', e)
except TypeError as e:
    print('TypeError:', e)

try:
    person.id = "1234"  # raises TypeError
except TypeError as e:
    print('TypeError:', e)

# 序列化以string返回
str = address_book.SerializeToString()
print('str: ', str)

# 从文件读取pb，并打印所有属性
pb_path = 'addressbook.pb'

with open(pb_path, 'wb') as f:
    f.write(str)


# 遍历所有的字段及对象属性
def ListPeople(address_book):
    for person in address_book.people:
        print("Person ID:", person.id)
        print("  Name:", person.name)
        if person.email is not None:
            print("  E-mail address:", person.email)

        for phone_number in person.phones:
            if phone_number.type == addressbook_pb2.Person.PhoneType.PHONE_TYPE_MOBILE:
                print("  Mobile phone #: ", end="")
            elif phone_number.type == addressbook_pb2.Person.PhoneType.PHONE_TYPE_HOME:
                print("  Home phone #: ", end="")
            elif phone_number.type == addressbook_pb2.Person.PhoneType.PHONE_TYPE_WORK:
                print("  Work phone #: ", end="")
            print(phone_number.number)


address_book = addressbook_pb2.AddressBook()

# 读取已经存在的文件
with open(pb_path, "rb") as f:
    address_book.ParseFromString(f.read())

# 遍历打印所有属性
ListPeople(address_book)

# pb转json
json_string = json_format.MessageToJson(address_book)
print('pb2json_string: ', json_string)

pb_json_path = pb_path.replace(".pb", "_pb.json")
with open(pb_json_path, 'w') as f:
    f.write(json_string)

# json_str 转pb对象
address2 = addressbook_pb2.AddressBook()
json_format.Parse(json_string,address2)
print('json_str2pb: ',address2)

# pb转dict
json_dict = json_format.MessageToDict(address_book)
print("pb2json_dict: ", json_dict)

pb_dict_path = pb_path.replace(".pb", "_pb_dict.json")
with open(pb_dict_path, 'w') as f:
    f.write(json.dumps(json_dict))

# json_dict 转pb
address3 = addressbook_pb2.AddressBook()
json_format.Parse(json_string,address3)
print('json_dict2pb: ',address3)