from tkinter import *
root = Tk()
c = Canvas(width=200, height=200, bg='green')
c.focus_set()
c.pack()
ball = c.create_oval(90, 90, 100, 100, fill='yellow')
c.bind('<Up>',   lambda event: c.move(ball, 0,-2))
c.bind('<Down>', lambda event: c.move(ball, 0, 2))
c.bind('<Left>', lambda event: c.move(ball,-2, 0))
c.bind('<Right>',lambda event: c.move(ball, 2, 0))
root.mainloop()