% cat gui2.py
from Tkinter import *

class Stooges(Frame):
    def __init__(self, parent=None):
        Frame.__init__(self, parent)
        self.pack()
        Button(self, text='Curly',
                     command=(lambda cb=self.message: cb('zoiks')) ).pack()
        Button(self, text='Moe',
                     command=(lambda me=self: me.message('boink')) ).pack()
        Button(self, text='Larry',
                     command=(lambda s=self, m='ouch': s.message(m)) ).pack()

    def message(self, x):
        print x

if __name__ == '__main__': Stooges().mainloop()

% python gui2.py
zoiks
boink
ouch