Pure-Python gRPC implementation for asyncio

This project is based on hyper-h2 and requires Python >= 3.6.

Example
- Client
- Server
Installation
protoc plugin
Contributing

Example

See examples directory in the project's repository for all available examples.

Client

import asyncio

from grpclib.client import Channel

# generated by protoc
from .helloworld_pb2 import HelloRequest, HelloReply
from .helloworld_grpc import GreeterStub


async def main():
    channel = Channel('127.0.0.1', 50051)
    greeter = GreeterStub(channel)

    reply: HelloReply = await greeter.SayHello(HelloRequest(name='Dr. Strange'))
    print(reply.message)

    channel.close()


if __name__ == '__main__':
    asyncio.run(main())

Server

import asyncio

from grpclib.utils import graceful_exit
from grpclib.server import Server

# generated by protoc
from .helloworld_pb2 import HelloRequest, HelloReply
from .helloworld_grpc import GreeterBase


class Greeter(GreeterBase):

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


async def main(*, host='127.0.0.1', port=50051):
    server = Server([Greeter()])
    with graceful_exit([server]):
        await server.start(host, port)
        print(f'Serving on {host}:{port}')
        await server.wait_closed()


if __name__ == '__main__':
    asyncio.run(main())

Installation

$ pip3 install grpclib protobuf

Bug fixes and new features are frequently published via release candidates:

$ pip3 install --upgrade --pre grpclib

For the code generation you will also need a protoc compiler, which can be installed with protobuf system package:

$ brew install protobuf  # example for macOS users
$ protoc --version
libprotoc ...

Or you can use protoc compiler from the grpcio-tools Python package:

$ pip3 install grpcio-tools
$ python3 -m grpc_tools.protoc --version
libprotoc ...

Note: grpcio and grpcio-tools packages are not required in runtime, grpcio-tools package will be used only during code generation.

`protoc` plugin

In order to use this library you will have to generate special stub files using plugin provided, which can be used like this:

$ python3 -m grpc_tools.protoc -I. --python_out=. --python_grpc_out=. helloworld/helloworld.proto

This command will generate helloworld_pb2.py and helloworld_grpc.py files.

Plugin, which implements --python_grpc_out option is available for protoc compiler as protoc-gen-python_grpc executable, which will be installed by pip/setuptools into your $PATH during installation of the grpclib library.

Contributing

Use Tox in order to test and lint your changes.

inewlife/grpclib