getting the return value of a function used in multiprocess

Question

Say I have the below code, a function that does something, which is initiated in a Process, and returns a value.

from multiprocessing import Process

def my_func(arg):
    return 'Hello, ' + arg

p1 = Process(target=my_func, args=('John',)
p1.start()
p1.join()

How do I get the return value of the function?

Solution

Answer

from multiprocessing import Process, Queue

Q = Queue()

def my_func(arg):
    Q.put('Hello, ' + arg)

p1 = Process(target=my_func, args=('John',))
p1.start()
print(Q.get())
p1.join()

Comments

[spaenigs]

Please add the missing brackets: Queue(), Process(target=my_func, args=('John',)).

[leonard vertighel]

This implies to modify your original my_func adding Q if you want to use it parallel