Tkinter - geometry managers (pack)

INTRODUCTION

Application layout in Tkinter is controlled with 'geometry managers' (pack, place, grid). Different frames can use different geometry managers.

PACK

'.pack()' uses a packing algorithm to place widgets in a Frame or window in a specified order.

The 'fill' keyword argument can be used to specify in which 'direction' the frames should fill.

The 'side' keyword argument can be used to specify on which side of the window the widget should be placed.

The 'anchor' keyword argument can be used to specify the position of a widget within its allocated space.

fill=tk.X   # horizontal direction
fill=tk.Y   # vertical direction
fill=tk.BOTH   # or fill="both"
side=tk.TOP   # default, side="top"
side=tk.BOTTOM   # or side="bottom"
side=tk.LEFT   # or side="left"
side=tk.RIGHT   # or side="right"
expand=tk.YES   # or expand=True
anchor=tk.N   # or tk.S, tk.E, tk.W, tk.CENTER (default)
anchor=tk.NE   # or tk.NW, tk.SE, tk.SW

# pack1.py
import tkinter as tk   # Py3

root = tk.Tk()

frame1 = tk.Frame(root, width=200, height=200, bg="red")
frame1.pack()

frame2 = tk.Frame(root, width=100, height=100, bg="yellow")
frame2.pack()

frame3 = tk.Frame(root, width=50, height=50, bg="blue")
frame3.pack()

root.mainloop()   # run the tkinter event loop

# pack2.py
import tkinter as tk   # Py3

root = tk.Tk()   # empty root

frame1 = tk.Frame(root, width=200, height=200, bg="red")
frame1.pack(fill=tk.X)

frame2 = tk.Frame(root, height=100, bg="yellow") # no width
frame2.pack(fill=tk.X)

frame3 = tk.Frame(root, height=50, bg="blue") # no width
frame3.pack(fill=tk.X)

root.mainloop()   # run the tkinter event loop

# pack3.py
import tkinter as tk   # Py3

root = tk.Tk()

frame1 = tk.Frame(root, width=200, height=200, bg="red")
frame1.pack(fill=tk.Y, side=tk.LEFT)

frame2 = tk.Frame(root, width=100, bg="yellow") # no height
frame2.pack(fill=tk.Y, side=tk.LEFT)

frame3 = tk.Frame(root, width=50, bg="blue") # no height
frame3.pack(fill=tk.Y, side=tk.LEFT)

root.mainloop()   # run the tkinter event loop

# pack4.py ('fill' and 'expand' keyword arguments)
import tkinter as tk   # Py3

root = tk.Tk()

frame1 = tk.Frame(root, width=200, height=200, bg="red")
frame1.pack(fill=tk.BOTH, side=tk.LEFT, expand=True)

frame2 = tk.Frame(root, width=100, bg="yellow") # no height
frame2.pack(fill=tk.BOTH, side=tk.LEFT, expand=True)

frame3 = tk.Frame(root, width=50, bg="blue") # no height
frame3.pack(fill=tk.BOTH, side=tk.LEFT, expand=True)

root.mainloop()   # run the tkinter event loop