[Tkinter] HOW TO: Use Globals In Module ???

[Webtest]

Esteemed Forum Participants and Lurkers:
Platform: Linux Mint 18.3 Mate 64-bit, Python 3.5.2 & Idle3
I am working on a Python 3 program using TKinter which is essentially a keystroke driven state machine. I want to segregate the different states in 'modules'. The 'root' TKinter window is global to the whole program, but I can't seem to make it visible to a module, EXCEPT I CAN pass it to a function in a module as a parameter.
How do I make it available to the function as a global object which is what I REALLY want to learn how to do?

Main Program:

# Module Test for Globals and Modules
import tkinter as tk

Groot = tk.Tk()  # Create the GLOBAL root window
Glabel1 = []     # Global Label identifier
GCOUNT = 0       # Global Keystroke counter

# Pull in the "setup" module
import setup
# Create and load the display label
setup.setup()

# #########  Keyboard 'Keypress' event handler  #########
def key(event):
    global GCOUNT
    GCOUNT += 1
    msg = '%d %r %d %d' %(GCOUNT,event.keysym,event.keysym_num,event.state)
    print(msg)
# #######################################################

# Bind the Keypress event to the 'key' event handler
Groot.bind_all('<Key>', key)
# Exit to the running event-driven app
Groot.mainloop()

Test Module:

# MODULE "setup.py" in moduletest
import tkinter as tk

# GLOBALS:
global Groot
global Glabel1

def setup():
    # Create and load the display label into the window
    prompt = '        Press any key        '
    Glabel1 = tk.Label(Groot, text=prompt, width=len(prompt), bg='yellow')
    Glabel1.pack()
    return()

Here is the error message:
Traceback (most recent call last):
File "/media/mint/python/keystroke.py", line 19, in <module>
setup.setup()
File "/media/mint/python/setup.py", line 18, in setup
Glabel1 = tk.Label(Groot, text=prompt, width=len(prompt), bg='yellow')
NameError: name 'Groot' is not defined

As I mentioned, I can get this to work by passing 'Groot' as a parameter to setup.setup(), but how can I use 'Groot' as a global WITHOUT having to pass it as a parameter?

Thank you for any and all comments, suggestions, and assistance in this effort.

Blessings in abundance, all the best, & ENJOY!
Art in Carlisle, PA USA