> * You can use named constants from ‘os’ for the purpose of specifying > exit status numbers.
Only on *nix. Even then it varies from platform to platform which constants you can use. I'd prefer to document the return status and use numbers/my own constants directly, that way supporting any platform (even windows, where its %ERRORLEVEL% --S -- https://mail.python.org/mailman/listinfo/python-list
