I have a Python script (running inside another application) which generates a bunch of temporary images. I then use subprocess to launch an application to view these.

When the image-viewing process exists, I want to remove the temporary images.

I can't do this from Python, as the Python process may have exited before the subprocess completes. I.e I cannot do the following:

p = subprocess.Popen(["imgviewer", "/example/image1.jpg", "/example/image1.jpg"])
p.communicate()
os.unlink("/example/image1.jpg")
os.unlink("/example/image2.jpg")

..as this blocks the main thread, nor could I check for the pid exiting in a thread etc

The only solution I can think of means I have to use shell=True, which I would rather avoid:

cmd = ['imgviewer']
cmd.append("/example/image2.jpg")

for x in cleanup:
    cmd.extend(["&&", "rm", x])

cmdstr = " ".join(cmd)
subprocess.Popen(cmdstr, shell = True)

This works, but is hardly elegant, and will fail with filenames containing spaces etc..

Basically, I have a background subprocess, and want to remove the temp files when it exits, even if the Python process no longer exists.