Tkinter, StringVar and dict

[Kevin Walzer]

I'm trying to manage user preferences in a Tkinter application by 
initializing some values that can then be configured from a GUI. The 
values are set up as a dict, like so:

   self.prefs= {
             'interface': '-en1',
             'verbose': '-v',
             'fontname': 'Courier',
             'point': 12,
             }

To link these values to the appropriate Tkinter variables, I'm using 
code like this:

  self.prefs['interface'] = StringVar()
  self.prefs['interface'].set("-en0") # initialize

This raises an error in Tkinter:

Exception in Tkinter callback
Traceback (most recent call last):
   File 
"/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/lib-tk/Tkinter.py", 
line 1403, in __call__
     return self.func(*args)
   File "/Users/kevin/Programming/packetstream/packetstream-classes.py", 
line 293, in setPrefs
     self.prefs['interface'] = StringVar()
   File 
"/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/lib-tk/Tkinter.py", 
line 3237, in __setitem__
     self.tk.call(self.name, 'configure', '-'+key, value)
TclError: unknown option "-interface"

Can someone help me smooth this out--to get dict key-values into a 
Tkinter variable like StringVar()?

Thanks.

-- 
Kevin Walzer
Code by Kevin
http://www.codebykevin.com