On 12Apr2015 17:00, Chris Angelico <ros...@gmail.com> wrote:
On Sun, Apr 12, 2015 at 4:33 PM, Cameron Simpson <c...@zip.com.au> wrote:
[...]
That's what try/finally is for. You can do your cleanup without caring
exactly what was raised.
Hmm, yes.
[...]
However, my Asynchron class really is a little special. I use Asynchron to
underpin a bunch of classes whose instances get fulfilled later, especially
callables that get queued and run at a suitable time (or which get run in
response to some external long awaited event). ...
Anyway, at some point in the above example "function" gets called (by the
infrastructure of "Later") with the supplied arguments as the Later
processes its queue.
So in this situation: should I catch and defer KeyboardInterrupt or
SystemExit? Maybe not, but the clean/naive implementation says to catch
absolutely everything.
That is a tough one. I would support either of BaseException and
Exception for this case, and whichever you pick, there will be a time
when you wish you'd picked the other. But at least now you get a
chance to think about it. [...]
On reflection I'm probably going to go after a bunch of my in-other-thread
things that handle "unknown" callables and do something like:
self.result = None
self.exc_info = None
try:
r = func(...)
except Exception:
self.exc_info = sys.exc_info
except BaseException as e:
self.exc_info = sys.exc_info
exception("unexpected BaseException: %s", e)
else:
self.result = r
to catch and report the weirdos. And I might write a little decorator to report
and reraise NameError to avoid certain times of silent asynchronous failure I
have to debug.
Colour me convinced, and +0.5 for proposals to retire bare "except".
Behold:
[hg/css]fleet*> hg clone . ../css-remove-except:
updating to branch default
2871 files updated, 0 files merged, 0 files removed, 0 files unresolved
Unnamed branch to change my practices:-)
Cheers,
Cameron Simpson <c...@zip.com.au>
... It beeped and said "Countdown initiated." Is that bad?
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