Как можно обмениваться данными между процессами

from multiprocessing import Process, Queue

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

q = Queue()
p = Process(target=worker, args=(q,))
p.start()
print(q.get())  # 'Hello from child!'
p.join()

from multiprocessing import Pipe, Process

def worker(conn):
    conn.send('Message')
    conn.close()

parent_conn, child_conn = Pipe()
p = Process(target=worker, args=(child_conn,))
p.start()
print(parent_conn.recv())  # 'Message'
p.join()

from multiprocessing import Process, Value

def increment(n):
    n.value += 1

num = Value('i', 0)
p = Process(target=increment, args=(num,))
p.start()
p.join()
print(num.value)  # 1