square-fractal.py

import tkinter as tk  # using Python 3
size = 600
m = tk.Tk()
canvas = tk.Canvas(m, width=size, height=size)
canvas.pack()
pos = 0
scale = 1/3

def rect(n, x, y, size, color):
    global scale
    if n == 0:
        return

    canvas.create_rectangle( x, y, x+size, y+size, fill=color, width='0' )

    rect( n-1, x, y + size/3, size * scale, '#0099ff' ) # left
    rect( n-1, x + size/3, y, size * scale, '#99ff00' ) # top
    rect( n-1, x + size/3, y + size/3*2, size * scale, 'orange' ) # bottom
    rect( n-1, x + size/3*2, y + size/3, size * scale, 'blue' ) # right

rect( 5, 0, 0, size, 'yellow' )

m.mainloop()