client.js

var zmq = require("zmq");

sock = zmq.socket("sub");
sock.connect("ipc:///tmp/keypad.zmq");

sock.on("message", function(msg) {
    console.log(msg);
});

server.py

#!/usr/bin/env python

import zmq
import sys

ctx = zmq.Context()
pub = ctx.socket(zmq.PUB)
pub.bind("ipc://" + sys.argv[1])

if __name__  == '__main__':
    while True:
        try:
            msg = input("> ")
            pub.send_string(msg)
        except:
            sys.exit(0