Catch exceptions

[Micha Reiser]

Hello, I try to write an owen exception handler, but now i have the 
Problem, that all exceptions which happens after I called app.MainLoop() 
i cant catch!?

    sys.stdout = output.stdout()
    sys.stderr = output.stderr()
    print 'Programm wird gestartet...'
    print 'stdout, stderr erfolgreich zugewiesen'
    try:
        app = wx.PySimpleApp(False)
        frame = MainFrame(None)
        frame.Show()
        app.SetTopWindow(frame)
        print 'Anwendung gestartet'
        app.MainLoop()
    except Exception, ex:
        sys.stderr.write(ex)

either it's not enought, when I only redirect the stderr. I must know, 
when the exception finished, that I can inform the user and send me an 
error email.

Any ideas...

Greeze Micha