#!/usr/bin/env python3
import subprocess
import time

#--- set both commands (connect / disconnect) below
connect_command = "xrandr --output DP-2 --pos 0x0 --mode 1920x1200 "\
                  "&& xrandr --output HDMI-0 --pos 1920x0 --mode 1920x1200 "\
                  "&& xrandr --output DP-3 --pos 3840x0 --mode 1920x1200 "\
                  "&& xrandr --output eDP-1-1 --off"

disconnect_command = ""
#---

while True:
    time.sleep(5)
    try:
        subprocess.Popen(["xrandr"])
    except:
        pass
    else:
        break


# function to get the output of xrandr
def get(cmd): return subprocess.check_output(cmd).decode("utf-8")
# - to count the occurrenc of " connected "
def count_screens(xr): return xr.count(" connected ")
# - to run the connect / disconnect command(s)
def run_command(cmd): subprocess.Popen(["/bin/bash", "-c", cmd])

# first count
xr1 = None

while True:
    time.sleep(5)
    # second count
    xr2 = count_screens(get(["xrandr"]))
    # check if there is a change in the screen state
    if xr2 != xr1:
        if xr2 == 4:
            # command to run if connected (two screens)
            time.sleep(2)
            run_command(connect_command)
        elif xr2 == 1:
            # command to run if disconnected (one screen)
            # uncomment run_command(disconnect_command) to enable, then also comment out pass
            pass
            # run_command(disconnect_command)
    # set the second count as initial state for the next loop
    xr1 = xr2