from Tkinter import *
class Hello(Frame):
def __init__(self, parent=None):
Frame.__init__(self, parent)
self.pack()
self.data = 42
self.make_widgets()
def make_widgets(self):
widget = Button(self, text='Button', command=self.message)
widget.pack(side=LEFT)
def message(self):
self.data = self.data + 1
print 'Hello %s!' % self.data
if __name__ == '__main__': Hello().mainloop()