[ python-Bugs-1513611 ] xml.sax.ParseException weirdness in python 2.5b1

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Bugs item #1513611, was opened at 2006-06-27 14:06
Message generated for change (Comment added) made by nnorwitz
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Category: XML
Group: Python 2.5
Status: Open
Resolution: None
>Priority: 9
Submitted By: Marien Zwart (marienz)
Assigned to: Nobody/Anonymous (nobody)
Summary: xml.sax.ParseException weirdness in python 2.5b1

Initial Comment:
There is something weird going on with xml.sax
exceptions, probably related to the xml/xmlcore shuffle:

from xml.sax import make_parser, SAXParseException
from StringIO import StringIO

parser = make_parser()

try:
    parser.parse(StringIO('invalid'))
except SAXParseException:
    print 'caught it!'

On python 2.4.3 this prints "caught it!". On python
2.5b1 the exception is not caught, because it is a
different  exception: an
xmlcore.sax._exceptions.SAXParseException. Printing the
SAXParseException imported from xml.sax gives "<class
'xml.sax._exceptions.SAXParseException'>".

Stumbled on this running the logilab-common (see
logilab.org) tests with python 2.5b1, but it seems
likely other code will be affected.

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>Comment By: Neal Norwitz (nnorwitz)
Date: 2006-07-26 20:31

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I think Martin is of the same opinion.  This needs to be
resolved soon.

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Comment By: Fred L. Drake, Jr. (fdrake)
Date: 2006-07-26 20:03

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I've managed to come up with a patch that solves this
specific issue, but it really deals with the symptom and not
the real problems.

While I think the "xmlcore" package was the right idea, I'm
not convinced it can be correctly implemented without
enormous effort at this time.  Given the release schedule,
it doesn't make sense to jump through those hoops.  The
previous hackery that made allowed the PyXML distribution to
"replace" the standard library version of the "xml" package
worked only because there was only one public name for
whichever was being used.  Moving to the "xmlcore" package
proved to be more than that hack could support.

I think the right thing to do for Python 2.5 is to revert
the changes that added the "xmlcore" package.  Further
investigation into a better approach can be made for Python 2.6.

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Comment By: Fred L. Drake, Jr. (fdrake)
Date: 2006-07-26 19:36

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The patch attached contains the wrong bug number, but it
really is for this issue.

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Comment By: Fred L. Drake, Jr. (fdrake)
Date: 2006-07-26 19:01

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Patch #1519796 does not do anything for this, based on the
current trunk.  I've attached a diff containing a test case.

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Comment By: Žiga Seilnacht (zseil)
Date: 2006-07-10 00:37

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This bug is simmilar to http://python.org/sf/1511497.
It is caused by absolute imports in xmlcore.sax.expatreader.
Patch #1519796 ( http://python.org/sf/1519796 )
should fix it.

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