[Doc] ROUTER-to-DEALER in C different from Python

[Joshuaalbert]

1. The bind protocols are different ipc in python vs tcp in C.
2. Python uses a singleton zmq.Context.instance() by C creates a new context.
3. There is not ready handshake in Python
4. The stopping is different.

A more accurate translation is:

# ROUTER-to-DEALER LRU Queue example in Python
import time
import random
from threading import Thread

import zmq

NBR_WORKERS = 10

def worker_task(worker_id):
    # Each worker has its own context
    context = zmq.Context()
    worker = context.socket(zmq.DEALER)
    identity = f"{worker_id}".encode('ascii')
    worker.setsockopt(zmq.IDENTITY, identity)
    worker.connect("tcp://localhost:5671")

    total = 0
    while True:
        # Tell broker we're ready (two‐frame empty + greeting)
        worker.send_multipart([b'', b'Hi Boss'])

        # Wait for broker reply (empty delimiter + workload)
        empty, workload = worker.recv_multipart()
        if workload == b'Fired!':
            print(f"Worker {worker_id} completed: {total} tasks")
            break

        total += 1
        # Do some random “work” (1–500 ms)
        time.sleep(random.randint(1, 500) / 1000.0)

    worker.close()
    context.term()


def broker_task():
    context = zmq.Context()
    broker = context.socket(zmq.ROUTER)
    broker.bind("tcp://*:5671")

    # Run for 5 seconds, then fire each worker in turn
    end_time = time.time() + 5
    workers_fired = 0

    while workers_fired < NBR_WORKERS:
        # Receive next ready worker: [ identity | empty | greeting ]
        identity, empty, greeting = broker.recv_multipart()

        # Decide whether to send work or fire
        if time.time() < end_time:
            broker.send_multipart([identity, b'', b'Work harder'])
        else:
            broker.send_multipart([identity, b'', b'Fired!'])
            workers_fired += 1

    broker.close()
    context.term()


if __name__ == "__main__":
    random.seed(time.time())

    # Launch workers (each in its own context/thread)
    for i in range(NBR_WORKERS):
        Thread(target=worker_task, args=(i,), daemon=True).start()

    # Start the broker loop (blocks until all workers are fired)
    broker_task()