[Python-Dev] CPython crash with '%o'
Guido van Rossum
guido at python.org
Wed Nov 14 20:41:16 CET 2007
Yes, and yes. There may be time still to fix the SystemError in 2.5.2!
On Nov 14, 2007 11:16 AM, Mike Stall <jmstall at exchange.microsoft.com> wrote:
> This is my first post, so here's a quick intro: I've recently joined the
> IronPython team at Microsoft, after about 6 years as a developer on the the
> .NET runtime (CLR).
> I'm currently trying to make IronPython match CPython's behavior regarding
> some % format string to a level of detail not documented by the spec.
> While exploring to determine what CPython's behavior is, I'm hitting a
> SystemError in CPython.
> Given the following snippet:
> class c(long):
> def __oct__(self):
> return '100'
> oct(x) # expected to print 100
> '%o' % x # expected to use print '5'
> It looks like in CPython, '%o' uses __int__ and so it should ignore __oct__
> and print 5.
> However, I'm hitting an SystemError in CPython with this snippet:
> Python 2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bit (Intel)]
> Type "help", "copyright", "credits" or "license" for more information.
> >>> class c(long):
> ... def __oct__(self):
> ... return '100'
> >>> x=c(5)
> >>> oct(x) # expected to print 100
> >>> '%o' % x # expected to use print '5'
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> SystemError: \loewis\25\python\Objects\stringobject.c:4236: bad argument to
> internal function
> Note that if c derives from 'int' instead of 'long', everything works as
> 1. Can somebody confirm that '%o' should not use __oct__ and that is uses
> __int__ instead, and that the correct output from ('%o' % x) is indeed 5?
> 2. Should I file a bug for the SystemError exception?
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> Python-Dev at python.org
--Guido van Rossum (home page: http://www.python.org/~guido/)
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