Tkinter - tk_focusNext broken for years?

[Helmut Jarausch]

Hi,

I'd like to bind the '<Return>' event to a function
which does some calculations (like a database lookup)
and then invoke  tk_focusNext.
I get an exception as many others have reported earlier, see
http://bugs.python.org/issue799428
There has even a patch been suggested. Why hasn't it been fixed -
I haven't seen a fix.
The problem can be reproduced by the following tiny script
I'm using Python 2.5.1 .

Should I fixed the Tkinter source myself or is there a workaround?

Many thanks for your help,
Helmut.
-------------------------------------------
import Tkinter as Tk

def Proc_Enter(Event) :
   print "Enter - normally lookup a database"
   Event.widget.tk_focusNext()

root= Tk.Tk()
Tk.Label(root,text='Name').grid(column=0,row=0,sticky=Tk.W)
Nm_input= Tk.StringVar()
Nm_entry= Tk.Entry(root,textvariable=Nm_input)
Nm_entry.bind('<Return>',Proc_Enter)
Nm_entry.grid(column=1,row=0,sticky=Tk.W)

Tk.Label(root,text='City').grid(column=0,row=1,sticky=Tk.W)
City_input= Tk.StringVar()
City_entry= Tk.Entry(root,textvariable=City_input)
City_entry.bind('<Return>',Proc_Enter)
City_entry.grid(column=1,row=1,sticky=Tk.W)

Tk.mainloop()
-------------------------------------------
 >>>>>>>>>>>>
Exception in Tkinter callback
Traceback (most recent call last):
   File "/usr/lib/python2.5/lib-tk/Tkinter.py", line 1403, in __call__
     return self.func(*args)
   File "FocusBug.py", line 6, in Proc_Enter
     Event.widget.tk_focusNext()
   File "/usr/lib/python2.5/lib-tk/Tkinter.py", line 479, in tk_focusNext
     return self._nametowidget(name)
   File "/usr/lib/python2.5/lib-tk/Tkinter.py", line 1064, in nametowidget
     if name[0] == '.':
TypeError: '_tkinter.Tcl_Obj' object is unsubscriptable
-------------------------------------------

-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany