# mouse1.py

from Tkinter import *

root = Tk()

def callback(event):
    print "clicked at", event.x, event.y 

frame = Frame(root, width=100, height=100)
frame.bind("<Button-1>", callback)
frame.pack()

root.mainloop()

# mouse2.py

from Tkinter import *

root = Tk()
canvas = Canvas(root, width=300, height=300)

def callback(event):
    canvas.create_oval(event.x, event.y, event.x+1, event.y+1)

canvas.bind("<Button-1>", callback)
canvas.bind("<B1-Motion>", callback)
canvas.pack()

root.mainloop()

# mouse3.py

from Tkinter import *

root = Tk()
canvas = Canvas(root, width=300, height=300)

def draw(event):
    global x0, y0
    canvas.create_line(x0, y0, event.x, event.y)
    x0, y0 = event.x, event.y

def down(event):
    global x0, y0
    x0, y0 = event.x, event.y

def up(event):
    global x0, y0
    if (x0, y0) == (event.x, event.y):
        canvas.create_line(x0, y0, x0+1, y0+1)

canvas.bind("<B1-Motion>", draw)
canvas.bind("<Button-1>", down)
canvas.bind("<ButtonRelease-1>", up)
canvas.pack()
root.mainloop()