Starting a process in Python and retrieving its window ID

Question

Let's say I run:

import subprocess;
P = subprocess.Popen(['gnome-terminal');

I then get an object P of the class Popen:

<subprocess.Popen object at 0xb72a9d0c>

How can I then retrieve the window identity of this subprocess?

Ultimately, I would like to manipulate the geometrical properties of the window spawned by the subprocess using wmctrl, but for this I need something known as the windows identity of the window (see the documentation of wmctrl)

To provide more context to the question, wmctrl -l outputs a list of windows running on the GNOME desktop, where the first column shows the window identity of each window. This is a hexadecimal number that I have noticed is different from the one included in the output reported by Popen above.

I checked the Popen documentation but I am not sure how to proceed from this point.

Any thoughts? Thanks!

Answer 1

An easy way to get the window ID is to use wmctrl -lp which will include the PID of the processes. Find the one that matches the Popen.pid of your subprocess and you'll find the window id of the process.