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

[Harlin Seritt]

I have the following script. Two widgets call the same function. How
can I tell inside of the called function which button called it?:

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

root = Tk()
button1 = Button(root, text='Button 1', command=say_hello)
button1.pack()
button2 = Button(root, text='Button 2', command=say_hello)
button2.pack()
root.mainloop()

Thanks,

Harlin Seritt