On 7/21/07, Andrew Dalke <[EMAIL PROTECTED]> wrote: > Posting here a expansion of a short discussion I had > after Guido's keynote at EuroPython. In this email > I propose eliminating the ".args" attribute from the > Exception type. It's not useful, and supporting it > correctly is complicated enough that it's often not > supported correctly >
This was originally proposed in PEP 352. This was the reason for the existence of the 'message' attribute as introduced in Python 2.5.. At PyCon 2007 I actually removed 'args' (see the p3yk_no_args_on_exc branch in svn: http://svn.python.org/view/python/branches/p3yk_no_args_on_exc/). But after making everyone at PyCon suffer through my swearing and frustration and talking with python-dev (and thus should be in the python-dev/python-3000 archives), the decision was made to not remove it (which is why 'message' is deprecated in Python 2.6). This was because the removal at the C level is very painful. There are many places within the code where a tuple is passed to various C functions that expect that tuple to be treated as multiple arguments to the exception constructor. But changing the semantics of a C function has already been labeled a no-no. So one would have to remove the C functions that construct exceptions with arguments and use a new one that only expects a single argument so not to have unexpected semantics. That sucks because those functions are all over. In the branch I just stuck the tuple into the 'message' attribute, but that caused its own issues as output was now a little funky since everything was considered a tuple, including single arguments. So while I totally understand the desire to ditch 'args' and just have 'message', doing so thoroughly and in any reasonable way that is not painful is not easy thanks to the C API. -Brett _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
