source: python/trunk/Demo/tkinter/matt/entry-simple.py

from Tkinter import *
import string

# This program  shows how to use a simple type-in box

class App(Frame):
    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.pack()

        self.entrythingy = Entry()
        self.entrythingy.pack()

        # and here we get a callback when the user hits return. we could
        # make the key that triggers the callback anything we wanted to.
        # other typical options might be <Key-Tab> or <Key> (for anything)
        self.entrythingy.bind('<Key-Return>', self.print_contents)

    def print_contents(self, event):
        print "hi. contents of entry is now ---->", self.entrythingy.get()

root = App()
root.master.title("Foo")
root.mainloop()