README.md

Twirpy

Python implementation of Twirp RPC framework (supports Twirp Wire Protocol v7).

This repo contains a protoc plugin that generates sever and client code and a pypi package with common implementation details.

For details about the twirp project, check https://github.com/twitchtv/twirp

Installation

Grab the protoc plugin to generate files with

go get -u github.com/verloop/twirpy/protoc-gen-twirpy

Add the twirp package to your project

pip install twirp

You'll also need uvicorn to run the server.

Generate and run

Use the protoc plugin to generate twirp server and client code.

We'll assume familiarity with the example from the docs. https://twitchtv.github.io/twirp/docs/example.html

protoc --python_out=./ --twirpy_out=./ ./haberdasher.proto

Server code

# server.py
import random

from twirp.asgi import TwirpASGIApp
from twirp.exceptions import InvalidArgument

from . import haberdasher_twirp, haberdasher_pb2

class HaberdasherService(object):
    def MakeHat(self, context, size):
        if size.inches <= 0:
            raise InvalidArgument(argument="inches", error="I can't make a hat that small!")
        return haberdasher_pb2.Hat(
            size=size.inches,
            color= random.choice(["white", "black", "brown", "red", "blue"]),
            name=random.choice(["bowler", "baseball cap", "top hat", "derby"])
        )


# if you are using a custom prefix, then pass it as `server_path_prefix`
# param to `HaberdasherServer` class.
service = haberdasher_twirp.HaberdasherServer(service=HaberdasherService())
app = TwirpASGIApp()
app.add_service(service)

Run the server with

uvicorn twirp_server:app --port=3000

Client code

# client.py
from twirp.context import Context
from twirp.exceptions import TwirpServerException

from . import haberdasher_twirp, haberdasher_pb2

client = haberdasher_twirp.HaberdasherClient("http://localhost:3000")

# if you are using a custom prefix, then pass it as `server_path_prefix`
# param to `MakeHat` class.
try:
    response = client.MakeHat(ctx=Context(), request=haberdasher_pb2.Size(inches=12))
    print(response)
except TwirpServerException as e:
    print(e.code, e.message, e.meta, e.to_dict())

Twirp Wire Protocol (v7)

Twirpy generates the code based on the protocol v7. This is a breaking change from the previous v5 and you can see the changes here.

This new version comes with flexibility to use any prefix for the server URLs and defaults to /twirp. To use an empty prefix or any custom prefix like /my/custom/prefix, pass it as a server_path_prefix param to server and clients. Check the example directory, which uses /twirpy as a custom prefix.

If you want to use the server and clients of v5, then use the 0.0.1 release.

Message Body Length

Currently, message body length limit is set to 100kb, you can override this by passing max_receive_message_length to TwirpASGIApp constructor.

# this sets max message length to be 10 bytes
app = TwirpASGIApp(max_receive_message_length=10)

Support and community

Python: #twirp. Join PySlackers here

Go: #twirp. Join Gophers community slack here

Standing on the shoulders of giants

• The initial version of twirpy was made from an internal copy of https://github.com/daroot/protoc-gen-twirp_python_srv
• The run_in_threadpool method comes from https://github.com/encode/starlette