GUI Tk Python

from Tkinter import *      
states = []
def onPress(i):                       
    states[i] = not states[i]   
root = Tk()
for i in range(10):
    chk = Checkbutton(root, text=str(i), command=(lambda i=i: onPress(i)) )
    chk.pack(side=LEFT)
    states.append(0)
root.mainloop()
print states