Getting the sender widget's name in function (Tkinter)

[infidel]

from Tkinter import Tk, Button

def say_hello(event):
    print 'hello!'
    print event.widget['text']

root = Tk()
button1 = Button(root, text='Button 1')
button1.bind('<Button-1>', say_hello)
button1.pack()
button2 = Button(root, text='Button 2')
button2.bind('<Button-1>', say_hello)
button2.pack() 
root.mainloop()