How can I share data between processes in Python using multiprocessing?

How can I share data between processes in Python using multiprocessing?

You can use shared memory or server process to share data. The multiprocessing module provides options like Value and Array.

Can you give me an example of using Value to share an integer?

Sure! Here's a simple example:

from multiprocessing import Process, Value

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

if __name__ == '__main__':
    num = Value('i', 0)  # Shared integer initialized to 0
    processes = [Process(target=increment, args=(num,)) for _ in range(5)]
    for p in processes:
        p.start()
    for p in processes:
        p.join()
    print(num.value)  # Output will be 5

What about sharing a list of data?

For sharing a list, you can use Array or a Manager object. Here's an example using Manager:

from multiprocessing import Process, Manager

def append_data(shared_list):
    shared_list.append(1)

if __name__ == '__main__':
    with Manager() as manager:
        shared_list = manager.list()  # Shared list
        processes = [Process(target=append_data, args=(shared_list,)) for _ in range(5)]
        for p in processes:
            p.start()
        for p in processes:
            p.join()
        print(list(shared_list))  # Output will be [1, 1, 1, 1, 1]