Tkinter, StringVar and dict

[Kevin Walzer]

James Stroud wrote:
> Kevin Walzer wrote:
>> 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.
>>
> 
> I overlooked this latter question.
> 
> Probably, your naming confusion above with self.prefs and the resulting 
> errors obscure your intention. But, were I to keep a dictionary of 
> StringVars for prefs, I would initialize it in this manner:
> 
> # somewhere in self
> defaults = {
>              'interface' : '-en1',
>              'verbose'   : '-v',
>              'fontname'  : 'Courier',
>              'point'     : 12
>             }
> self.prefs = dict((d,StringVar()) for d in defaults)
> for d in defaults:
>   self.prefs[d].set(defaults[d])
> 
> Note, of course, that you will need to access 'point' like this if you 
> want it back as an int:
> 
>   int(self.prefs['point'].get())
> 
> Because StringVars return strings from their get() method.
> 
> James
> 
Thanks, these snippets helped me work this out.



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