programa mouse

from Tkinter import *

alto = 500
ancho = 150


def paint(event):
    x1,y1 = (event.x -1), (event.y -1)
    x2,y2 = (event.x +1), (event.y + 1)
    panel.create_oval(x1,y1,x2,y2, fill='red')

def borrartodo():
    panel.delete('all')




master= Tk()
master.title('pinta con el mouse')

panel= Canvas(master, width=ancho, height= alto)
panel.pack(expand = YES, fill = BOTH )
panel.bind("",paint)

mensaje= Label(master,text='presione o arrastre con el mouse')
mensaje.pack(side=BOTTOM)

boton=Button(master, text='borrar', command = borrartodo)
boton.pack(side=BOTTOM)

master.mainloop()