Re-raising exceptions with modified message

[Christoph Zwerschke]

Kay Schluehr wrote:
> If you are sure that the exception isn't caught on another level just
> use the following showtraceback() function, manipulate it's output
> slightly and terminate your program with sys.exit()

That's what I want to avoid. In my case the error is displayed and 
evaluated in a completly different piece of software.

-- Chris