Suppressing Implicit Chained Exceptions (Python 3.0)

[andrew cooke]

I have some (library) code where an exception is caught and, since the
underlying cause is rather obscure, a different exception is raised that
more clearly explains the issue to the caller.

However, when printed via format_exc(), this new exception still has the
old exception attached via the mechanism described at
http://www.python.org/dev/peps/pep-3134/ (this is Python 3.0).

Is there any simple way to stop this?  It's rather annoying and
misleading, as it exposes a lot of internal detail that the caller does
not understand or want.  This is marked as an "open issue" in the PEP
described above.

Thanks,
Andrew