from tkinter import *
from tkinter.ttk import *

def plus_one():
    """adds 1 to the counter"""
    global click_counter, counter_label

    click_counter += 1
    counter_label["text"] = str(click_counter)

def minus_one():
    """takes 1 away from the counter"""
    global click_counter, counter_label

    click_counter -= 1
    counter_label["text"] = str(click_counter)

def main():
    """main function"""

    global click_counter, counter_label

    click_counter = 0
    window = Tk()

    counter_label = Label(window, text=str(click_counter))
    counter_label.grid(row=0, column=0)

    plus_one_button = Button(window, text="+1", command=plus_one)
    plus_one_button.grid(row=2, column=0)

    minus_one_button = Button(window, text="-1", command=minus_one)
    minus_one_button.grid(row=2, column=1)

    window.mainloop()

main()