Python3-如何使用protobuf 3(图文详解)

步骤：

1.下载protoc（protocol compiler）

2.编写.proto文件

3.编译（生成xxxx_pb2.py）

4.引用xxxx_pb2.py

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详解：

【下载protoc】

https://github.com/google/protobuf/releases

根据自己的平台下载对应的编译器，我的是win10-64位：

解压到C:/Program Files下面：

设置环境变量：这一步使你在本地任何地方使用protoc这个指令

（右击“此电脑”。。。）

测试protoc:

新打开一个命令行：输入protoc --version，如果将输出版本号，说明protoc安装好了

【编写.proto协议文件】

新建一个hello_protobuf文件夹，再在里面建一个空的protobuf文件夹（专门用于存放协议文件)：

用pycharm打开该文件夹：

效果：

新建协议文件：

在hello_protobuf/protobuf/目录下手动创建addressbook.proto文件：

并在addressbook.proto中输入：

syntax = "proto3";


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

  enum PhoneType {
    MOBILE = 0;
    HOME = 1;
    WORK = 2;
  }

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

  repeated PhoneNumber phones = 4;
}

message AddressBook {
  repeated Person people = 1;
}

【编译】：

打开命令行，CD到hello_protobuf/protobuf/下面，执行protoc --python_out=./ addressbook.proto

没有输出说明未出错。

新生成hello_protobuf/protobuff/addressbook_pb2.py——这是我们python最终要用的协议文件了

【写测试】：

输入addressbook_test_writing.py

在该文件中输入：

from protobuf import addressbook_pb2


def PromptForAddress(person):
    person.id = 1
    person.name = "mc.meng"
    person.email = "menghaocheng@qq.com"
    phone_number = person.phones.add()
    phone_number.number = "18565772445"
    phone_number.type = addressbook_pb2.Person.MOBILE


def write_test():

    address_book = addressbook_pb2.AddressBook()

    address_book_file = "./data/addressbook.txt"

    try:
      f = open(address_book_file, "rb")
      address_book.ParseFromString(f.read())
      f.close()
    except IOError:
      print(address_book_file + ": Could not open file.  Creating a new one.")

    PromptForAddress(address_book.people.add())

    f = open(address_book_file, "wb")
    f.write(address_book.SerializeToString())
    f.close()


if __name__ == "__main__":
    write_test()

在创建hello_protobuf/data/目录用于存放数据：

在pycharm中按F5运行：

将输出：

Connected to pydev debugger (build 172.3968.37)
./data/addressbook.txt: Could not open file.  Creating a new one.


Process finished with exit code 0

此时在hello_protobuf/data/下生成 了addressbook.txt文件

【读测试】：

用相同的方法合建address_test_reading.py，然后输入以下内容：

import protobuf.addressbook_pb2 as addressbook_pb2


def ListPeople(address_book):
  for person in address_book.people:
    print("Person ID:", person.id)
    print("  Name:", person.name)
    print("  E-mail address:", person.email)

    for phone_number in person.phones:
      if phone_number.type == addressbook_pb2.Person.MOBILE:
        print("  Mobile phone #: ")
      elif phone_number.type == addressbook_pb2.Person.HOME:
        print("  Home phone #: ")
      elif phone_number.type == addressbook_pb2.Person.WORK:
        print("  Work phone #: ")
      print(phone_number.number)


def read_test():
    address_book = addressbook_pb2.AddressBook()
    address_book_file = "./data/addressbook.txt"

    f = open(address_book_file, "rb")
    address_book.ParseFromString(f.read())
    f.close()

    ListPeople(address_book)


if __name__ == "__main__":
    read_test()

按F5运行，将输出：

Connected to pydev debugger (build 172.3968.37)
Person ID: 1
  Name: mc.meng
  E-mail address: menghaocheng@qq.com
  Mobile phone #: 
18565772445

Process finished with exit code 0