xprop_get_active_window_name.py

import subprocess

def active_window_name():
    window_id_cmd = ["/usr/bin/xprop", "-root", "_NET_ACTIVE_WINDOW"]
    window_id = subprocess.check_output(window_id_cmd).decode("utf-8").strip().split()[-1]
    window_name_cmd = ["/usr/bin/xprop", "-id", window_id, "_NET_WM_NAME"]
    window_name = subprocess.check_output(window_name_cmd).decode("utf-8").strip()[29:-1]
    return window_name
    
print(active_window_name())