如何在python中同时运行这两个命令？

import threading
import os

def command1():
    os.system("command1")

def command2():
    os.system("command2")

if __name__ == "__main__":
    thread1 = threading.Thread(target=command1)
    thread2 = threading.Thread(target=command2)
    thread1.start()
    thread2.start()
    thread1.join()
    thread2.join()

import multiprocessing
import os

def command1():
    os.system("command1")

def command2():
    os.system("command2")

if __name__ == "__main__":
    process1 = multiprocessing.Process(target=command1)
    process2 = multiprocessing.Process(target=command2)
    process1.start()
    process2.start()
    process1.join()
    process2.join()