Q:

Notify-send not working in python script run with sudo

I'm writing a python script that is run with sudo permissions.  At some point, I would like to send a notification to the user.  I have noticed that notify-send does not work as a root user, so I tried to run it as the actual user by doing su $SUDO_USER -c notify-send ..., but this does not work either. 
The first of the following functions works when run without sudo privileges.  None of them work when run with sudo.  Any idea why? 
def notify(message):

    subprocess.run(['notify-send', '-i', 'utilities-terminal', 'Notification Title', message],
                   stdout=subprocess. PIPE,
                   stderr=subprocess. PIPE,
                   check=True)

def notifySudo(message):

    subprocess.run(['su', os.environ['SUDO_USER'], '-c', 'notify-send', '-i', 'utilities-terminal', 'Notification Title', message],
                   stdout=subprocess. PIPE,
                   stderr=subprocess. PIPE,
                   check=True)

A:

So after a bit of research, I've found the solution:
import os

def notify(title, message):

    userID = subprocess.run(['id', '-u', os.environ['SUDO_USER']],
                            stdout=subprocess. PIPE,
                            stderr=subprocess. PIPE,
                            check=True).stdout.decode("utf-8").replace('\n', '')

    subprocess.run(['sudo', '-u', os.environ['SUDO_USER'], 'DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/{}/bus'.format(userID), 
                    'notify-send', '-i', 'utilities-terminal', title, message],
                    stdout=subprocess. PIPE,
                    stderr=subprocess. PIPE,
                    check=True)

