Problem with running external process

[ToMasz]

Yes, each time the process is created, it remains.

os.waitpid(-1, os.WNOHANG) doesn't work before starting  the process
for the first time.

I tried this:

pid = os.fork()
if pid == 0:
      os.execl('ext_script.py','ext_script.py')
else:
      (pid,status) = os.waitpid(pid, 0)

It seems to work without leaving zombies.