1# Change window_name to the name of the window object, i.e. root
2window_name.geometry("500x500")
3# To ensure widgets resize:
4widget_name.pack(fill="both", expand=True)
1#import statement
2from tkinter import *
3#create GUI Tk() variable
4gui = Tk()
5#set window size
6gui.geometry("widthxheight")
1 window = Tk() # or window = TopLevel()
2 # "350x150" == window size (350 pixels wide and 150 pixels high)
3 # "+220+80" == window position (220 pixels from the left screen margin and
4 # 80 pixels from the top screen margin
5 window.geometry("350x150+220+80")