On Mon, Feb 18, 2008 at 3:44 PM, Guido van Rossum <[EMAIL PROTECTED]> wrote: > I don't know if you're done with this already, but there's a lot of > experience suggesting such sweeps are quite dangerous. In the past, > whenever a sweep across the entire stdlib was done, it's always caused > a few breakages, some of which didn't get caught until the next > release. > > Things to worry about with these two changes: > > raise X, y -> raise X(y): this is incorrect if y is a tuple; *only* if > it's a tuple, the correct translation is raise X(*y). But 2to3 can't > know that (unless the tuple is written out in place).
Yep. That's something I'd eventually like to correct by adding an interactive mode (if 2to3 is unsure about a given fix, it can ask the user). It's on my todo list for PyCon. Collin Winter > except X as y: in 3.0 this has different semantics -- y is explicitly > deleted at the end of the except block. I don't know if this is also > the semantics implemented in 2.6 (I think it should be), but again > this can cause som equite subtle breakages that are hard to catch > automatically. > > And since both of these are about exceptions, there's a high > likelihood that some occurrences are not reached by a unittest. > > IOW, while I'm not dead set against it (I agree with your motivation > in principle) I worry that in practice it may destabilize things., and > would prefer a different approach where these things are only changed > when someone is revising the module anyway. > > --Guido > > > On Feb 17, 2008 8:57 AM, Christian Heimes <[EMAIL PROTECTED]> wrote: > > > > Good evening everybody! > > > > I like to run the 2to3 tool with raise and except fixers over the 2.6 > > sources. The raise fixer changes "raise Exception, msg" to "raise > > Exception(msg)" and the except fixer replaces "except Exception, err" by > > "except Exception as err". In my humble opinion the Python stdlib should > > give proper examples how write good code. > > > > During the migration period from the 2.x series to 3.x we have two > > obvious ways to write code. Let's stick to the new and preferred way. > > > > Oh and please use the new syntax for patches, too. It makes my job with > > svnmerge a little bit easier. > > > > Thanks! > > > > Christian > > > > _______________________________________________ > > Python-Dev mailing list > > Python-Dev@python.org > > http://mail.python.org/mailman/listinfo/python-dev > > Unsubscribe: > http://mail.python.org/mailman/options/python-dev/guido%40python.org > > > > > > -- > --Guido van Rossum (home page: http://www.python.org/~guido/) > > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > http://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > http://mail.python.org/mailman/options/python-dev/collinw%40gmail.com > _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
