Built on top of
asyncio, Python's standard asynchronous I/O framework, it
provides an elegant coroutine-based API.
Here's a client that says "Hello world!":
#!/usr/bin/env python import asyncio import websockets async def hello(uri): async with websockets.connect(uri) as websocket: await websocket.send("Hello world!") asyncio.get_event_loop().run_until_complete( hello('ws://localhost:8765'))
And here's an echo server (for Python ≥ 3.6):
#!/usr/bin/env python import asyncio import websockets async def echo(websocket, path): async for message in websocket: await websocket.send(message) asyncio.get_event_loop().run_until_complete( websockets.serve(echo, 'localhost', 8765)) asyncio.get_event_loop().run_forever()
Does that look good? Start here.
Why should I use
The development of
websockets is shaped by four principles:
- Simplicity: all you need to understand is
msg = await ws.recv()and
websocketstakes care of managing connections so you can focus on your application.
websocketsis built for production; for example it was the only library to handle backpressure correctly before the issue became widely known in the Python community.
websocketsis heavily tested. Continuous integration fails under 100% branch coverage. Also it passes the industry-standard Autobahn Testsuite.
- Performance: memory use is configurable. An extension written in C accelerates expensive operations. It's pre-compiled for Linux, macOS and Windows and packaged in the wheel format for each system and Python version.
Documentation is a first class concern in the project. Head over to Read the Docs and see for yourself.
Professional support is available if you — or your company — are so inclined. Get in touch.
(If you contribute to
websockets and would like to become an official
support provider, let me know.)
Why shouldn't I use
- If you prefer callbacks over coroutines:
websocketswas created to provide the best coroutine-based API to manage WebSocket connections in Python. Pick another library for a callback-based API.
- If you're looking for a mixed HTTP / WebSocket library:
websocketsaims at being an excellent implementation of RFC 6455: The WebSocket Protocol and RFC 7692: Compression Extensions for WebSocket. Its support for HTTP is minimal — just enough for a HTTP health check.
- If you want to use Python 2:
asynciowhich only works on Python 3.
websocketsrequires Python ≥ 3.4.
websockets is released under the BSD license.