I have a python program that uses `subprocess.Popen` to launch another process (python process or whatever), and after launching it I save the child's PID to a file. Let's suppose that suddenly the parent process dies (because of an exception or whatever). Is there any way to access again to the object returned by `Popen`?

I mean, the basic idea is to read the file at first, and if it exists and it has a PID written on it, then access to that process someway, in order to know the return code or whatever. If there isn't a PID, then launch the process with `Popen`.

Thanks a lot!!