external process not terminating

[Larry Martell]

I have an app (using 2.7) that processes requests. When a request of
type "A" is received I need to start an external process.

When a request of type "B" is received I need to check and see if that
external process has completed or not and then do some stuff depending
on if it has or not.

The issue I am running into is that when the external process is done
is does not exit, it goes into a zombie state, e.g.:

1 Z root     13703 13644  0  80   0 -     0 exit   09:37 ?
00:00:00 [python] <defunct>

Initially I was starting the process with Popen like this:

DEVNULL = open(os.devnull, "wb")
subprocess.Popen(cmd+args, stdin=DEVNULL, stdout=DEVNULL,
stderr=DEVNULL, close_fds=True)

I tried using os.spawn:

os.spawnv(os.P_NOWAIT, 'python', cmd+args)

But still the process did not exit.

Anyone know how I can get the external process to terminate when done?

TIA!