An implementation of the WebSocket Protocol (RFC 6455 & 7692)
.. image:: logo/horizontal.svg :width: 480px :alt: websockets
|licence| |version| |pyversions| |tests| |docs| |openssf|
.. |licence| image:: https://img.shields.io/pypi/l/websockets.svg :target: https://pypi.python.org/pypi/websockets
.. |version| image:: https://img.shields.io/pypi/v/websockets.svg :target: https://pypi.python.org/pypi/websockets
.. |pyversions| image:: https://img.shields.io/pypi/pyversions/websockets.svg :target: https://pypi.python.org/pypi/websockets
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.. |docs| image:: https://img.shields.io/readthedocs/websockets.svg :target: https://websockets.readthedocs.io/
.. |openssf| image:: https://bestpractices.coreinfrastructure.org/projects/6475/badge :target: https://bestpractices.coreinfrastructure.org/projects/6475
websockets
?websockets is a library for building WebSocket_ servers and clients in Python with a focus on correctness, simplicity, robustness, and performance.
.. _WebSocket: https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API
Built on top of asyncio
, Python's standard asynchronous I/O framework, the
default implementation provides an elegant coroutine-based API.
An implementation on top of threading
and a Sans-I/O implementation are also
available.
Documentation is available on Read the Docs. <https://websockets.readthedocs.io/>
_
.. copy-pasted because GitHub doesn't support the include directive
Here's an echo server with the asyncio
API:
.. code:: python
#!/usr/bin/env python
import asyncio
from websockets.server import serve
async def echo(websocket):
async for message in websocket:
await websocket.send(message)
async def main():
async with serve(echo, "localhost", 8765):
await asyncio.Future() # run forever
asyncio.run(main())
Here's how a client sends and receives messages with the threading
API:
.. code:: python
#!/usr/bin/env python
from websockets.sync.client import connect
def hello():
with connect("ws://localhost:8765") as websocket:
websocket.send("Hello world!")
message = websocket.recv()
print(f"Received: {message}")
hello()
Does that look good?
Get started with the tutorial! <https://websockets.readthedocs.io/en/stable/intro/index.html>
_
websockets
?The development of websockets
is shaped by four principles:
Correctness: websockets
is heavily tested for compliance with
:rfc:6455
. Continuous integration fails under 100% branch coverage.
Simplicity: all you need to understand is msg = await ws.recv()
and
await ws.send(msg)
. websockets
takes care of managing connections
so you can focus on your application.
Robustness: websockets
is built for production. For example, it was
the only library to handle backpressure correctly
_ before the issue
became widely known in the Python community.
Performance: memory usage is optimized and configurable. A C extension 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.
.. _Read the Docs: https://websockets.readthedocs.io/ .. _handle backpressure correctly: https://vorpus.org/blog/some-thoughts-on-asynchronous-api-design-in-a-post-asyncawait-world/#websocket-servers
websockets
?If you prefer callbacks over coroutines: websockets
was 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: websockets
aims
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 an HTTP health check.
If you want to do both in the same server, look at HTTP frameworks that
build on top of websockets
to support WebSocket connections, like
Sanic_.
.. _Sanic: https://sanicframework.org/en/
Bug reports, patches and suggestions are welcome!
To report a security vulnerability, please use the Tidelift security contact
_. Tidelift will coordinate the fix and disclosure.
.. _Tidelift security contact: https://tidelift.com/security
For anything else, please open an issue_ or send a pull request
_.
.. _issue: https://github.com/python-websockets/websockets/issues/new .. _pull request: https://github.com/python-websockets/websockets/compare/
Participants must uphold the Contributor Covenant code of conduct
_.
.. _Contributor Covenant code of conduct: https://github.com/python-websockets/websockets/blob/main/CODE_OF_CONDUCT.md
websockets
is released under the BSD license
_.
.. _BSD license: https://github.com/python-websockets/websockets/blob/main/LICENSE