[Zope3-dev] Please, no bare 'except:' clauses!

[Barry A. Warsaw]

>>>>> "JH" == Jeremy Hylton <jeremy@zope.com> writes:

    JH> This is sufficient for dealing with sloppy exception handling,
    JH> though.  If the transaction is read-only and the except clause
    JH> swallows a ReadConflictError, the app may never find out that
    JH> a consistency problem occurred.

    JH> Thinking more... I suppose a Connection could have a
    JH> per-transaction marker that says it has detected a read
    JH> conflict.  If the marker is set, it could refuse to load any
    JH> more objects.  That sounds a bit draconian.  I'm not sure what
    JH> makes sense.

Won't multiversion concurrency control eliminate read conflicts?

    JH> There are very few places where bare except is needed.  At
    JH> least some of those places, the bare except is in place
    JH> because it's very hard to tell what exception Python might
    JH> raise (calling int() is an example).  In cases like that, the
    JH> StandardError solution is a good one.

Let's see, int() can raise TypeError and ValueError.  What else?

-Barry