create process that "ensure" cleaning sub-process

clean_process.py

@contextlib.contextmanager
def clean_process(*args, **kwargs):
    def kill_proc_tree(pid, sig=signal.SIGTERM, include_parent=True, timeout=None, on_terminate=None):
        assert pid != os.getpid(), "won't kill myself"

        try:
            parent = psutil.Process(pid)
        except psutil.NoSuchProcess:
            return

        children = parent.children(recursive=True)
        if include_parent:
            children.append(parent)
        for p in children:
            try:
                p.send_signal(sig)
            except psutil.NoSuchProcess:
                pass
        gone, alive = psutil.wait_procs(children, timeout=timeout, callback=on_terminate)
        return (gone, alive)

    proc = subprocess.Popen(*args, **kwargs)
    try:
        yield proc
    finally:
        kill_proc_tree(proc.pid)

About try... finally in python https://stackoverflow.com/a/49262664/2091555

What is guaranteed is that if execution flows out of the whole try-finally construct, it will pass through the finally to do so.