txZMQ allows to integrate easily ØMQ sockets into Twisted event loop (reactor).

txZMQ supports both CPython and PyPy.

Non-Python library required:

• ØMQ library >= 2.1 (heavily tested with 2.1.4)

Python packages required:

• pyzmq (for CPython)
• pyzmq-ctypes (for PyPy)
• Twisted

txZMQ introduces support for general ØMQ sockets by class ZmqConnection that can do basic event loop integration, sending-receiving messages in non-blocking manner, scatter-gather for multipart messages.

txZMQ uses ØMQ APIs to get file descriptor that is used to signal pending actions from ØMQ library IO thread running in separate thread. This is used in a custom file descriptor reader, which is then added to the Twisted reactor.

From this class, one may implement the various patterns defined by ØMQ. For example, special descendants of the ZmqConnection class, ZmqPubConnection and ZmqSubConnection, add special nice features for PUB/SUB sockets.

Request/reply pattern is achieved via XREQ/XREP sockets and classes ZmqXREQConnection, ZmqXREPConection.

Other socket types could be easily derived from ZmqConnection.

Here is an example of creating a txZMQ server:

from txzmq import ZmqEndpoint, ZmqFactory, ZmqPubConnection

def publish(server):
    data = str(time.time())
    print "Publishing %r ..." % data
    server.publish(data)
    print "Done."
    reactor.callLater(1, publish, server)

def onConnect(server):
    print "Connected!"
    publish(server)

endpoint = ZmqEndpoint("bind", "ipc:///tmp/sock")
server = ZmqPubConnection(endpoint)
deferred = server.listen(ZmqFactory())
deferred.addCallback(onConnect)
reactor.run()

Here is an example of creating a txZMQ client:

from txzmq import ZmqEndpoint, ZmqFactory, ZmqPubConnection

class MySubscriber(ZmqSubConnection):

    def gotMessage(self, message, tag):
        print "Message received: %s (%s)" % (message, tag)

def onConnect(client):
    print "Connected!"
    client.subscribe("")

endpoint = ZmqEndpoint("connect", "ipc:///tmp/sock")
client = MySubscriber(endpoint)
deferred = client.connect(ZmqFactory())
deferred.addCallback(onConnect)
reactor.run()

Examples similar to this are available in the source code. You can run them from the command line with passed options. Be sure to read the comments at the beginning of the example files for usage information.

Source code for txZMQ is available at github; forks and pull requests are welcome.

To start hacking, fork at github and clone to your working directory. To use the Makefile (for running unit tests, checking for PEP8 compliance and running pyflakes), you will want to have virtualenv installed (it includes a pip installation).

Create a branch, add some unit tests, write your code, check it and test it! Some useful make targets are:

• make env
• make check
• make test

If you don't have an environment set up, a new one will be created for you in ./env. Additionally, txZMQ will be installed as well as required development libs.