How to exchange data between processes in Python?

In Python, for inter-process communication, you can use the multiprocessing module, which provides several mechanisms:

1. Queues — thread-safe queues that allow processes to safely exchange objects.

from multiprocessing import Process, Queue

def worker(q):
    q.put('Data from child process')

if __name__ == '__main__':
    q = Queue()
    p = Process(target=worker, args=(q,))
    p.start()
    print(q.get())  # Receive data
    p.join()

2. Pools with return values — you can get results from processes using apply_async methods.

3. Shared objects (Value, Array) — allow creating objects of primitive types shared between processes.

4. Managers — allow creating more complex shared objects, such as dictionaries and lists.

from multiprocessing import Process, Manager

def worker(d):
    d['key'] = 'value'

if __name__ == '__main__':
    with Manager() as manager:
        d = manager.dict()
        p = Process(target=worker, args=(d,))
        p.start()
        p.join()
        print(d)  # {'key': 'value'}

5. Sockets or other IPC mechanisms — for more complex scenarios, you can use sockets, pipes, or files.

The choice depends on the task: for simple data exchange, Queue or Manager are the best options.