#!/usr/local/bin/python
from Tkinter import *                   # get widgets

class Hello(Frame):                     # container subclass
    def __init__(self, parent=None):
        Frame.__init__(self, parent)    # superclass init
        self.pack()
        self.make_widgets()             # attach to self

    def make_widgets(self):
        widget = Button(self, text='Hello',
                              command=self.onPress)
        widget.pack(side=LEFT)

    def onPress(self):
        print 'Hi.'                     # write to stdout

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