What methods are used for inter-process communication in operating systems?

The main methods used for inter-process communication (IPC) in operating systems are:

• Pipes — allow data to be transmitted as a byte stream between processes, usually related.
• Named Pipes (FIFO) — similar to pipes but have a name in the filesystem and can be used between unrelated processes.
• Sockets — provide data exchange between processes, both on the same computer and over a network.
• Shared Memory — a memory area allocated for quick data exchange accessible by multiple processes.
• Semaphores — used for synchronizing access to shared resources.
• Message Queues — allow processes to exchange structured messages through a queue.

In Python, IPC can be implemented using the multiprocessing module, which provides high-level objects for data exchange such as queues (Queue), pipes (Pipe), and support for shared memory via Value and Array.

Example of using a queue for data exchange between processes in Python:

from multiprocessing import Process, Queue

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

if __name__ == '__main__':
    q = Queue()
    p = Process(target=worker, args=(q,))
    p.start()
    print(q.get())  # Receive message from the child process
    p.join()