python script via udev rules for hotplugging display port monitor

Question

I'm running i3-wm on a ubuntu install. i3 doesn't auto-detect and configure the monitor set up when I (dis)connect the miniDP cable. I've tried implementing a udev rule that runs a python script which in turn executes xrandr commands. I can run the script from the command line and it works, but it doesn't seem to run when I unplug the mDP cable. Here is the contents of my udev rules which is located in /etc/udev/rules.d/monitor.rules:

KERNEL=="card0", SUBSYSTEM=="drm", ENV{XAUTHORITY}="/var/run/gdm/auth-for-ME-OlbTje/database", RUN+="/path/to/my/script/monitor_toggle.py"

Per suggestions in the comments, I added logging with code from here. The script runs now and I can see my logging info via /var/log/syslog but..... a million processes start running and hang the system. I have to hard reset the machine. Here is the script in question.

import subprocess
import logging
from logging.handlers import SysLogHandler
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
syslog = SysLogHandler(address = '/dev/log')
logger.addHandler(syslog)

home_dual       = "/home/vazquez/.screenlayout/i3_home_dual.sh"
home_single     = "/home/vazquez/.screenlayout/i3_home_single.sh"
monitor_toggle  = "/home/vazquez/bin/monitor_toggle.py"


def main():
    logger.debug("In Main")
    card = "/sys/class/drm/card0-DP-1"
    logger.debug("Checking status of mDP")
    status = subprocess.check_output(["cat","/sys/class/drm/card0-DP-1/status"] )
    status = status.decode( 'ascii' )
    logger.debug("status: {0}".format(status))

    # If the mDP is disconnected run home_single
    if 'disconnected' in status:
        # ret = subprocess.check_output(monitor_toggle)
        logger.debug("montor")
        try:
            dead = subprocess.check_output(["sh", home_single])
        except:
            logger.debug( "ret1 = {0}".format(dead) )
    # else the mDP is connect, run home_dual    
    else:
        logger.debug("In else")
        logger.debug("connecting external monitor")
        # ret = subprocess.check_output(monitor_toggle)
        try:
            beef = subprocess.check_output(["sh", home_dual])
        except:
            logger.debug(" ret 2: {0}".format(beef) )


if __name__=="__main__":
    main()

/var/log/syslog output

tail  /var/log/syslog
Apr 26 21:35:01 vazquez-dev CRON[3243]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Apr 26 21:36:11 vazquez-dev In Main
Apr 26 21:36:11 vazquez-dev Checking status of mDP
Apr 26 21:36:11 vazquez-dev status: disconnected
Apr 26 21:36:11 vazquez-dev montor 
Apr 26 21:39:34 vazquez-dev In Main
Apr 26 21:39:34 vazquez-dev Checking status of mDP
Apr 26 21:39:34 vazquez-dev status: connected
Apr 26 21:39:34 vazquez-dev In else
Apr 26 21:39:34 vazquez-dev connecting external monitor