bspwm events screensaver toggling

screensaver.py

#!/usr/bin/python3 -u
''' Screensaver fullscreen toggling '''

import subprocess
import json

def class_find(windows, name):
    ''' Find className '''
    for window in windows.values():
        if window['client']['className'] == name:
            return True
    return False

def main():
    ''' Main '''
    windows = {}
    process = subprocess.Popen(['/usr/bin/bspc', 'control', '--subscribe', 'window_state'],
                               stdout=subprocess.PIPE, bufsize=1, universal_newlines=True)

    for line in process.stdout:
        line = json.loads(line)
        if line['client']['state'] == 'fullscreen':
            windows[line['client']['window']] = line
        elif line['client']['window'] in windows:
            del windows[line['client']['window']]
        else:
            continue

        try:
            subprocess.check_call(['/usr/bin/pgrep', 'i3lock'])
        except subprocess.CalledProcessError:
            pass
        else:
            continue

        xset_output = subprocess.check_output(['/usr/bin/xset', 'q']).decode('UTF-8')
        if 'DPMS is Enabled' in xset_output and windows:
            if class_find(windows, 'Kodi'):
                pass
            else:
                subprocess.check_call(['/usr/bin/xset', '-dpms'])
        elif 'DPMS is Disabled' in xset_output:
            if (windows and class_find(windows, 'Kodi')) or not windows:
                subprocess.check_call(['/usr/bin/xset', '+dpms'])

if __name__ == '__main__':
    main()

The proper way to do this would be to build an initial world view based on the output of query -T and then update that world view in response to window_{state,manage,unmanage} events.