1 from Tkinter import *

     2 import string

     3 

     4 # This program  shows how to make a typein box shadow a program variable.

     5 

     6 class App(Frame):

     7     def __init__(self, master=None):

     8         Frame.__init__(self, master)

     9         self.pack()

    10 

    11         self.entrythingy = Entry(self)

    12         self.entrythingy.pack()

    13 

    14         self.button = Button(self, text="Uppercase The Entry",

    15                              command=self.upper)

    16         self.button.pack()

    17 

    18         # here we have the text in the entry widget tied to a variable.

    19         # changes in the variable are echoed in the widget and vice versa.

    20         # Very handy.

    21         # there are other Variable types. See Tkinter.py for all

    22         # the other variable types that can be shadowed

    23         self.contents = StringVar()

    24         self.contents.set("this is a variable")

    25         self.entrythingy.config(textvariable=self.contents)

    26 

    27         # and here we get a callback when the user hits return. we could

    28         # make the key that triggers the callback anything we wanted to.

    29         # other typical options might be <Key-Tab> or <Key> (for anything)

    30         self.entrythingy.bind('<Key-Return>', self.print_contents)

    31 

    32     def upper(self):

    33         # notice here, we don't actually refer to the entry box.

    34         # we just operate on the string variable and we

    35         # because it's being looked at by the entry widget, changing

    36         # the variable changes the entry widget display automatically.

    37         # the strange get/set operators are clunky, true...

    38         str = string.upper(self.contents.get())

    39         self.contents.set(str)

    40 

    41     def print_contents(self, event):

    42         print "hi. contents of entry is now ---->", self.contents.get()

    43 

    44 root = App()

    45 root.master.title("Foo")

    46 root.mainloop()