Autobahn|Python

   

Autobahn|Python is a subproject of Autobahn and provides open-source implementations of

• The WebSocket Protocol
• The Web Application Messaging Protocol (WAMP)

in Python running on Twisted and asyncio.

WebSocket allows bidirectional real-time messaging on the Web and WAMP adds asynchronous Remote Procedure Calls and Publish & Subscribe on top of WebSocket.

You can use Autobahn|Python to create clients and servers in Python speaking just plain WebSocket or WAMP:

• framework for WebSocket / WAMP clients and servers
• compatible with Python 2.6, 2.7, 3.3 and 3.4
• runs on CPython, PyPy and Jython
• runs under Twisted and asyncio
• implements WebSocket RFC6455, Draft Hybi-10+, Hixie-76
• implements WebSocket compression
• implements WAMPv1 and WAMPv2 (upcoming)
• high-performance, fully asynchronous implementation
• best-in-class standards conformance (100% strict passes with Autobahn Testsuite)
• message-, frame- and streaming-APIs for WebSocket
• supports TLS (secure WebSocket) and proxies
• Open-source (Apache 2 license)

Python support

Support for Autobahn|Python on Twisted and asyncio is as follows:

Python	Twisted	asyncio	Notes
CPython 2.6	yes	yes	asyncio support via trollius
CPython 2.7	yes	yes	asyncio support via trollius
CPython 3.3	yes	yes	asyncio support via tulip
CPython 3.4+	yes	yes	asyncio in the standard library
PyPy 2.2+	yes	yes	asyncio support via trollius
Jython 2.7+	yes	?	Issues: 1, 2

Installation

You will need at least one of Twisted or Asyncio as your networking framework.

Asyncio comes bundled with Python 3.4. For Python 3.3, install it from here. For Twisted, please see here.

Install from the Python Package Index using Pip:

pip install autobahn

You can also specify install variants

pip install autobahn[twisted,accelerate]

The latter will automatically install Twisted and native acceleration packages when running on CPython.

pip install autobahn[asyncio,accelerate]

The latter will automatically install asyncio backports when required and native acceleration packages when running on CPython.

To install from sources, clone the repo

git clone [email protected]:tavendo/AutobahnPython.git

checkout a tagged release

cd AutobahnPython
git checkout v0.7.2

and install

cd autobahn
python setup.py install

You can also use Pip for the last step, which allows to specify install variants

pip install -e .[twisted]

Autobahn|Python has the following install variants:

1. twisted: Install Twisted as a dependency
2. asyncio: Install asyncio backports when required
3. accelerate: Install native acceleration packages on CPython
4. compress: Install packages for non-standard WebSocket compression methods
5. serialization: Install packages for additional WAMP serialization formats (currently MsgPack)

Getting Started

The "Hello, world!" of WebSocket is probably an echo server:

class MyServerProtocol(WebSocketServerProtocol):

   def onConnect(self, request):
      print("Client connecting: {}".format(request.peer))

   def onOpen(self):
      print("WebSocket connection open.")

   def onMessage(self, payload, isBinary):
      if isBinary:
         print("Binary message received: {} bytes".format(len(payload)))
      else:
         print("Text message received: {}".format(payload.decode('utf8')))

      ## echo back message verbatim
      self.sendMessage(payload, isBinary)

   def onClose(self, wasClean, code, reason):
      print("WebSocket connection closed: {}".format(reason))

Complete examples are here:

• WebSocket Echo (Twisted-based)
• WebSocket Echo (Asyncio-based)

Autobahn comes with lots of examples with ready-to-run code.

For complete API documentation, please consult the reference documentation.

For more information, including some tutorials, please visit the project's homepage.

Depending on Autobahn

To require Autobahn|Python as a dependency of your package, include the following in your setup.py:

install_requires = ["autobahn>=0.7.2"]

You can also depend on an install variant which automatically installs respective packages:

install_requires = ["autobahn[twisted,accelerate]>=0.7.2"]

Upgrading from Autobahn < 0.7.0

Starting with release 0.7.0, Autobahn|Python now supports both Twisted and asyncio as the underlying network library. This required changing module naming, e.g.

Autobahn|Python < 0.7.0:

 from autobahn.websocket import WebSocketServerProtocol

Autobahn|Python >= 0.7.0:

 from autobahn.twisted.websocket import WebSocketServerProtocol

or

 from autobahn.asyncio.websocket import WebSocketServerProtocol 

Two more small changes (also see the interface definition now available):

1. WebSocketProtocol.sendMessage: renaming of parameter binary to isBinary (for consistency with onMessage)
2. ConnectionRequest no longer provides peerstr, but only peer, and the latter is a plain, descriptive string (this was needed since we now support both Twisted and asyncio, and also non-TCP transports)

Upgrading from Autobahn < 0.8.0

Starting with release 0.8.0, Autobahn|Python now supports WAMPv2. This required changing module naming for WAMPv1 (Twisted), e.g.

Autobahn|Python < 0.8.0:

 from autobahn.wamp import WampServerFactory

Autobahn|Python >= 0.8.0:

 from autobahn.wamp1.protocol import WampServerFactory

Note that WAMPv1 will be deprecated with the 0.9.0 release.

Performance

Autobahn|Python is portable, well tuned code. You can further accelerate performance by

• Running under PyPy or
• on CPython, install the native accelerators wsaccel and ujson (you can use the install variant acceleration for that)

Get in touch

Get in touch on IRC #autobahn on chat.freenode.net, follow us on Twitter or join the mailing list.