Last modified: Feb 02, 2025 By Alexander Williams

Python pyzmq.zmq_poll() Guide

Python's pyzmq.zmq_poll() is a powerful function for managing ZeroMQ sockets. It allows you to monitor multiple sockets for events efficiently. This guide will help you understand how to use it effectively.

What is pyzmq.zmq_poll()?

pyzmq.zmq_poll() is a function in the PyZMQ library. It is used to poll ZeroMQ sockets for incoming messages or other events. This is useful in applications where you need to handle multiple sockets simultaneously.

Why Use pyzmq.zmq_poll()?

Using pyzmq.zmq_poll() can improve the performance of your application. It allows you to avoid busy-waiting and efficiently manage multiple sockets. This is especially useful in real-time systems.

Basic Usage

Here is a simple example of how to use pyzmq.zmq_poll(). This example demonstrates polling two sockets for incoming messages.


import zmq

context = zmq.Context()
socket1 = context.socket(zmq.PULL)
socket2 = context.socket(zmq.PULL)

socket1.bind("tcp://*:5555")
socket2.bind("tcp://*:5556")

poll = zmq.Poller()
poll.register(socket1, zmq.POLLIN)
poll.register(socket2, zmq.POLLIN)

while True:
    socks = dict(poll.poll())
    if socket1 in socks:
        message = socket1.recv()
        print(f"Received from socket1: {message}")
    if socket2 in socks:
        message = socket2.recv()
        print(f"Received from socket2: {message}")
    

In this example, we create two ZeroMQ sockets and bind them to different ports. We then register these sockets with a poller and continuously poll for incoming messages.

Handling Multiple Events

pyzmq.zmq_poll() can handle multiple events simultaneously. You can register multiple sockets and monitor them for different types of events, such as incoming messages or connection status changes.

Advanced Usage

For more advanced usage, you can combine pyzmq.zmq_poll() with other PyZMQ features. For example, you can use it with asynchronous programming to build highly scalable applications.

Example with Asynchronous Programming

Here is an example that combines pyzmq.zmq_poll() with Python's asyncio library. This allows you to handle multiple sockets asynchronously.


import zmq
import asyncio

async def poll_sockets():
    context = zmq.Context()
    socket1 = context.socket(zmq.PULL)
    socket2 = context.socket(zmq.PULL)

    socket1.bind("tcp://*:5555")
    socket2.bind("tcp://*:5556")

    poll = zmq.Poller()
    poll.register(socket1, zmq.POLLIN)
    poll.register(socket2, zmq.POLLIN)

    while True:
        socks = dict(poll.poll())
        if socket1 in socks:
            message = socket1.recv()
            print(f"Received from socket1: {message}")
        if socket2 in socks:
            message = socket2.recv()
            print(f"Received from socket2: {message}")
        await asyncio.sleep(0.1)

asyncio.run(poll_sockets())
    

This example demonstrates how to use pyzmq.zmq_poll() in an asynchronous context. The await asyncio.sleep(0.1) ensures that the event loop is not blocked.

Conclusion

pyzmq.zmq_poll() is a versatile function for managing ZeroMQ sockets. It allows you to efficiently monitor multiple sockets and handle events in real-time. Whether you are building a simple application or a complex system, pyzmq.zmq_poll() can help you achieve your goals.

For more information on handling streams in Python, check out our guides on Python httpx.stream_ws() and Python httpx.stream_async().