Thank you guys for those good advices (and the very interesting example of AST hacking).
However, this was an example of use for Exception.args. It does not alleviate my concerns about the fact that the args attribute is poorly designed for standard Exceptions. It is as if the Exception design was only made for end users (display of a string in an interpreter) without thinking about original ways to use them :-) Seb -- http://mail.python.org/mailman/listinfo/python-list
