gistfile1.py

from Tkinter import *
import time, thread

master = Tk()
master.title("Switch test")

w = Canvas(master, width=200, height=200)
w.pack()

w.create_rectangle(0, 0, 200, 100, fill="white")
w.create_rectangle(0, 200, 200, 100, fill="white")


def on(event):
    w.create_rectangle(0, 200, 200, 100, fill="white")
    w.create_rectangle(0, 0, 200, 100, fill="yellow")
    thread.start_new_thread ( turnback, ())

def off(event):
    w.create_rectangle(0, 0, 200, 100, fill="white")
    w.create_rectangle(0, 200, 200, 100, fill="yellow")
    thread.start_new_thread ( turnback, ())

def turnback():
    time.sleep(3)
    w.create_rectangle(0, 0, 200, 100, fill="white")
    w.create_rectangle(0, 200, 200, 100, fill="white")


w.bind_all('<space>', on)
w.bind_all('<Return>', off)

master.mainloop(  )