[Python-Dev] PEP 415: Implementing PEP 409 differently

[Benjamin Peterson]

2012/2/26 Nick Coghlan <ncoghlan at gmail.com>:
> Thanks for writing that up. I'd be amenable if the PEP was clearly
> updated to say that ``raise exc from cause`` would change from being
> syntactic sugar for ``_hidden = exc; _hidden.__cause__ = cause; raise
> exc`` (as it is now) to ``_hidden = exc; _hidden.__cause__ = cause;
> _hidden.__suppress_context__ = True; raise exc``. The patch should
> then be implemented accordingly (including appropriate updates to the
> language reference).

I add the following lines to the PEP:

To summarize, ``raise exc from cause`` will be equivalent to::

    exc.__cause__ = cause
    exc.__suppress_context__ = cause is None
    raise exc


-- 
Regards,
Benjamin