# Tk_key_move.py

# Tk_key_move.py

from Tkinter import *
root = Tk()
canvas = Canvas(root, width=400, height= 400, bg="white")
canvas.pack()
rect = canvas.create_rectangle(100, 100, 110, 110, fill='blue')
x_velocity = 0
y_velocity = 0

keys_being_held_down = set()
key_accelerations = {
    "Up": (0, -10),
    "Down": (0, 10),
    "Left": (-10, 0),
    "Right": (10, 0)
}

def key_pressed(event):
    global x_velocity, y_velocity

    #ignore autorepeat events
    if event.keysym in keys_being_held_down:
        return

    keys_being_held_down.add(event.keysym)
    acceleration = key_accelerations[event.keysym]
    x_velocity += acceleration[0]
    y_velocity += acceleration[1]

def key_released(event):
    global x_velocity, y_velocity
    keys_being_held_down.remove(event.keysym)
    acceleration = key_accelerations[event.keysym]
    x_velocity -= acceleration[0]
    y_velocity -= acceleration[1]

def tick():
    canvas.move(rect, x_velocity, y_velocity)
    root.after(50,tick)

for key in key_accelerations:
    root.bind("<{}>".format(key), key_pressed)
    root.bind("<KeyRelease-{}>".format(key), key_released)

root.after(100, tick)
root.mainloop()