A Simple Tkinter Control Program--Slight Problem

[W. eWatson]

Here's what I think the author meant in discussing a control variable sample 
program. <http://effbot.org/tkinterbook/entry.htm>

from Tkinter import *

v=Tk.StringVar()

e = Entry(master, textvariable=v)
e.pack()
e.focus_set()

v.set("a default value")
s = v.get()

mainloop()

The problem is that Python objects to v=.
     v=Tk.StringVar()
AttributeError: class Tk has no attribute 'StringVar'

What corrects this?
-- 
                                W. eWatson

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