[Python-Dev] Py2.5 release schedule
"Martin v. Löwis"
martin at v.loewis.de
Sun Jul 30 23:34:30 CEST 2006
Fred L. Drake, Jr. schrieb:
> On Sunday 30 July 2006 15:44, Barry Warsaw wrote:
> > if isinstance(obj, ClassType) or isinstance(obj, type(type))
>
> Looks like you've got a possible name clash in the second isinstance. ;-)
Nah, that's rather an entry to the obfuscated Python contest.
The two occurrences of type really mean to refer to the same
thing; this is the test whether obj _is a_ new-style class.
Normally, you would write isinstance(obj, type), but that gives
a TypeError in 2.1 (isinstance() arg 2 must be a class or type).
In 2.1, type(type) is FunctionType, so the test should
fail (in the context, as obj ought to be a string, an exception
object, or an exception type). In 2.2 and later, we have
>>> type(type) is type
1 # sometimes True instead
I think I would have rewritten as
try:
# Instantiate it if possible and necessary
exc = exc()
except AttributeError: # no __call__; it's already an object
pass
(assuming that the mailman exceptions don't have __call__) or as
if not isinstance(exc, Exception):
exc = exc()
(assuming that string exceptions are gone, but the code below
already assumes that exc should be an object that supports
exc.reason_notice())
Regards,
Martin
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