Python zeromq — Multiple Publishers To a Single Subscriber?

Question

I\'d like to write a python script (call it parent) that does the following:

(1) defines a multi-dimensional numpy

Answer 1

The sub channel doesn't have to be the one to bind, so you can have the subscriber bind, and each of the children pub channels can connect to that and send their messages. In this particular case, I think the multiprocessing module is a better fit, but I thought it bore mentioning:

import zmq
import threading

# So that you can copy-and-paste this into an interactive session, I'm
# using threading, but obviously that's not what you'd use

# I'm the subscriber that multiple clients are writing to
def parent():
    context = zmq.Context()
    socket = context.socket(zmq.SUB)
    socket.setsockopt(zmq.SUBSCRIBE, 'Child:')
    # Even though I'm the subscriber, I'm allowed to get this party 
    # started with `bind`
    socket.bind('tcp://127.0.0.1:5000')

    # I expect 50 messages
    for i in range(50):
        print 'Parent received: %s' % socket.recv()

# I'm a child publisher
def child(number):
    context = zmq.Context()
    socket = context.socket(zmq.PUB)
    # And even though I'm the publisher, I can do the connecting rather
    # than the binding
    socket.connect('tcp://127.0.0.1:5000')

    for data in range(5):
        socket.send('Child: %i %i' % (number, data))
    socket.close()

threads = [threading.Thread(target=parent)] + [threading.Thread(target=child, args=(i,)) for i in range(10)]
for thread in threads:
    thread.start()

for thread in threads:
    thread.join()

In particular, the Core Messaging Patterns part of the documentation discusses the fact that for the patterns, either side can bind (and the other connect).