# disclaimer: behaviour as expected! - EPERM if there are pgroup-processes in the old session
import os
import psutil

from time import sleep

root = os.getpid()
sleep(1)
os.setpgid(0,0)
pid = os.fork()
if pid:
    sleep(1)
    os.setpgid(0, os.getppid())
    sleep(1)
    os.setsid()