On Sun, Apr 12, 2015 at 7:37 AM, Cameron Simpson <c...@zip.com.au> wrote: > On 11Apr2015 21:21, Chris Angelico <ros...@gmail.com> wrote: >> >> But I agree, it would be very nice if Python 3 could have abolished >> the truly confusing part of this, where "except:" catches everything. >> Forcing people to spell it "except BaseException:" would fix all of >> this. How hard is it to deprecate and then remove that, same as string >> exceptions were removed? > > > I guess I'll go over there to oppose it then. > > Why? It makes it harder to write portable python 2/3 code and does not add > any semantic advantage. > > Unless there's a common root exception class in Python 2, which I believe > there isn't, you can't catch all exceptions in python 2 without the > "except:" syntax. Which means the _only_ way to have some code in both 2 > and 3 that does it requires 2 codebases. > > As one who tries to have his code run in both 2 (usually recent 2, like > 2.6/2.7) and 3, this change would cause a signification breakage for me > without bringing any semantic benefits.
Can you give an example of a place where in Py2 you absolutely have to catch everything, and don't have control over the code, *and* are trying to do a one-codebase routine with Py3 compatibility? If you're trying for 2/3 compatibility, you'll need to have all your exceptions derive from BaseException anyway. At very worst, it could be turned into a compat-only syntax feature, like the u"spam" noise prefix on Unicode strings - serving absolutely no purpose in Py3 code, and ideally, able to be removed at some point post-2020. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
