grpclib

# 1. Define your service in a .proto file (e.g., helloworld.proto):
# syntax = "proto3";
# package helloworld;
# message HelloRequest { string name = 1; }
# message HelloReply { string message = 1; }
# service Greeter { rpc SayHello (HelloRequest) returns (HelloReply); }

# 2. Generate Python code from the .proto file:
# python3 -m grpc_tools.protoc -I. --python_out=. --grpclib_python_out=. helloworld.proto

# 3. Server implementation (server.py)
import asyncio
from grpclib.utils import graceful_exit
from grpclib.server import Server

# Generated by protoc from helloworld.proto
from helloworld_pb2 import HelloReply
from helloworld_grpc import GreeterBase

class Greeter(GreeterBase):
    async def SayHello(self, stream):
        request = await stream.recv_message()
        message = f'Hello, {request.name}!'
        await stream.send_message(HelloReply(message=message))

async def main_server(*, host='127.0.0.1', port=50051):
    server = Server([Greeter()])
    # Note: graceful_exit isn't supported in Windows
    with graceful_exit([server]):
        await server.start(host, port)
        print(f'Serving on {host}:{port}')
        await server.wait_closed()

# 4. Client implementation (client.py)
from grpclib.client import Channel

# Generated by protoc from helloworld.proto
from helloworld_pb2 import HelloRequest, HelloReply
from helloworld_grpc import GreeterStub

async def main_client():
    async with Channel('127.0.0.1', 50051) as channel:
        greeter = GreeterStub(channel)
        reply = await greeter.SayHello(HelloRequest(name='Dr. Strange'))
        print(reply.message)

# To run the server and then the client:
# if __name__ == '__main__':
#    asyncio.run(main_server())
#    # In another terminal, run:
#    # asyncio.run(main_client())