Python function to run in background

May 10, 2024

I have two functions, "one" and "two". I want function "one" to run in the background as two runs. Basically, one executes, and while it’s waiting, execute two.

import time

def one(msg, a):
    time.sleep(a)
    print(msg)
def two(msg, a):
    time.sleep(a)
    print(msg)

one("Hello, ", 2) # Run this in the background as the other function runs
two("World!", 1)

I tried coroutines but it didn’t really work out for me because one ran after the other.

>Solution :

You can use multi-threading to have one function run in the background. You can use multiprocessing as well, but in most scenarios, simply creating a thread is better than creating an entire separate process. In your case, you can change your code to look like this:

import time, threading

def one(msg, a):
    time.sleep(a)
    print(msg)
def two(msg, a):
    time.sleep(a)
    print(msg)

thread = threading.Thread(target=one, args=("Hello, ", 2))
thread.start()
two("World!", 1)

If however, you want to use multi-processing, you can use this code instead:

import time
from multiprocessing import Process

def one(msg, a):
    time.sleep(a)
    print(msg)

def two(msg, a):
    time.sleep(a)
    print(msg)

if __name__ == '__main__':
    p1 = Process(target=one, args=("Hello, ", 2))
    p1.start()
    
    p2 = Process(target=two, args=("World!", 1))
    p2.start()

Both of these will achieve the same result.