[ python-Bugs-847665 ] XMLGenerator.startElementNS dies on EMPTY_NAMESPACE attribut

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Bugs item #847665, was opened at 2003-11-23 10:21
Message generated for change (Comment added) made by akuchling
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Category: XML
Group: Python 2.3
Status: Open
Resolution: None
Priority: 5
Submitted By: Stuart Bishop (zenzen)
Assigned to: Nobody/Anonymous (nobody)
Summary: XMLGenerator.startElementNS dies on EMPTY_NAMESPACE attribut

Initial Comment:
from xml.sax.saxutils import XMLGenerator

g = XMLGenerator(encoding='utf8')
STREAM_NAMESPACE = 'http://etherx.jabber.org/streams'
CLIENT_NAMESPACE = 'jabber:client'
g.startDocument()
g.startPrefixMapping('stream', STREAM_NAMESPACE)
g.startPrefixMapping('client', CLIENT_NAMESPACE)
g.startElementNS( 
    (STREAM_NAMESPACE, 'stream'), 'stream',
    {(None,'xmlns'): CLIENT_NAMESPACE}
    )

Dies with:
Traceback (most recent call last):
  File "tst.py", line 11, in ?
    g.startElementNS( 
  File "/System/Library/Frameworks/Python.framework/
Versions/2.3/lib/python2.3/xml/sax/saxutils.py", line 124, in 
startElementNS
    name = self._current_context[name[0]] + ":" + name[1]
KeyError: 'x'


Changing the end of XMLGenerator.startElementNS to the 
following makes it work the way I expect:

        for (name, value) in attrs.items():
            if name[0] is None:
                name = name[1]
            else:
                name = self._current_context[name[0]] + ":" + 
name[1]
            self._out.write(' %s=%s' % (name, 
quoteattr(value)))
        self._out.write('>')


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>Comment By: A.M. Kuchling (akuchling)
Date: 2005-12-04 15:01

Message:
Logged In: YES 
user_id=11375

I don't understand your second example; it uses saxutils to
parse a file.  What's it got to do with XMLGenerator?

----------------------------------------------------------------------

Comment By: Stuart Bishop (zenzen)
Date: 2003-11-24 14:36

Message:
Logged In: YES 
user_id=46639

This method also appears to have trouble emmitting tags without a 
namespace prefix:

import xml.sax
import xml.sax.handler
import xml.sax.saxutils
x = '''<?xml version="1.0"?><mechanisms xmlns='urn:ietf:
params:xml:ns:xmpp-sasl'
>'''
parser = xml.sax.make_parser()
parser.setFeature(xml.sax.handler.feature_namespaces, True)
parser.setContentHandler(xml.sax.saxutils.XMLGenerator())
parser.feed(x)

dies with:
Traceback (most recent call last):
  File "tst.py", line 30, in ?
    parser.feed(x)
  File "/System/Library/Frameworks/Python.framework/Versions/
2.3/lib/python2.3/xml/sax/expatreader.py", line 207, in feed
    self._parser.Parse(data, isFinal)
  File "/System/Library/Frameworks/Python.framework/Versions/
2.3/lib/python2.3/xml/sax/expatreader.py", line 337, in 
start_element_ns
    AttributesNSImpl(newattrs, qnames))
  File "/System/Library/Frameworks/Python.framework/Versions/
2.3/lib/python2.3/xml/sax/saxutils.py", line 116, in startElementNS
    name = self._current_context[name[0]] + ":" + name[1]
TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'



I've attached my current replacement startElementNS method 
which appears to fix both this and the previous issue.

----------------------------------------------------------------------

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