stop a subprocess python
import os
import signal
import subprocess
# The os.setsid() is passed in the argument preexec_fn so
# it's run after the fork() and before exec() to run the shell.
pro = subprocess.Popen(cmd, stdout=subprocess.PIPE,
shell=True, preexec_fn=os.setsid)
os.killpg(os.getpgid(pro.pid), signal.SIGTERM) # Send the signal to all the process groups