[XML-SIG]PyXML and XPath : simple Path expression seems to crash with brutality

[Gaël Pegliasco]

Hello,

I'm trying to test xpath with this simple program :

import xml.dom.minidom
from xml.xpath.Context import Context
import xml.xpath

s = '''<?xml version="1.0"?>
    <root>
    <elem attr="1">Some<test>roto</test> text</elem>
    <elem attr="2">More text</elem>
    </root>'''

d = xml.dom.minidom.parseString(s)

result=xml.xpath.Evaluate( '//elem/test', d.documentElement )

for node in result:
    print node, node.nodeName

But it crashed with  the message below:

Traceback (most recent call last):
  File "./xpath.py", line 12, in ?
    result=xml.xpath.Evaluate( '//elem/test', d.documentElement )
  File "/usr/local/lib/python2.3/site-packages/_xmlplus/xpath/__init__.py", line
70, in Evaluate
    retval = parser.new().parse(expr).evaluate(con)
  File
"/usr/local/lib/python2.3/site-packages/_xmlplus/xpath/ParsedAbbreviatedAbsoluteLocationPath.py",
line 44, in evaluate
    sub_rt.extend(self._rel.select(context))
  File
"/usr/local/lib/python2.3/site-packages/_xmlplus/xpath/ParsedRelativeLocationPath.py",
line 23, in evaluate
    raise Exception("Expected node set from relative expression.  Got %s"%str(rt))
Exception: Expected node set from relative expression.  Got ()



If I try with this syntax, its works :
result=xml.xpath.Evaluate( 'descendant::elem/test', d.documentElement )

I have the same problem with more complex requests :

Like "//DOC.PRINCIPAL//FILE/@VOL_PAGE_SEQ" that I must rewrite like
"descendant::DOC.PRINCIPAL/descendant::FILE/@VOL_PAGE_SEQ" else it crashed with
a different message :

Traceback (most recent call last):
  File "/edika/vol1/users/gpegliasco/projets/dev/tools/src/xpathgrep.py", line
233, in ?
    searchInFile( file, searchedObject )
  File "/edika/vol1/users/gpegliasco/projets/dev/tools/src/xpathgrep.py", line
77, in searchInFile
    listNodes = xpath.Evaluate( xpathquery, context=con ) 
  File "/usr/local/lib/python2.3/site-packages/_xmlplus/xpath/__init__.py", line
70, in Evaluate
    retval = parser.new().parse(expr).evaluate(con)
  File
"/usr/local/lib/python2.3/site-packages/_xmlplus/xpath/ParsedAbbreviatedAbsoluteLocationPath.py",
line 44, in evaluate
    sub_rt.extend(self._rel.select(context))
  File
"/usr/local/lib/python2.3/site-packages/_xmlplus/xpath/ParsedRelativeLocationPath.py",
line 21, in evaluate
    rt = self._left.select(context)
  File
"/usr/local/lib/python2.3/site-packages/_xmlplus/xpath/ParsedAbbreviatedRelativeLocationPath.py",
line 52, in evaluate
    res = Set.Union(res,subRt)
  File "/usr/local/lib/python2.3/site-packages/_xmlplus/xpath/Set.py", line 25,
in Union
    return compare + filter(lambda x,compare = compare:x not in compare,loop)
TypeError: can only concatenate list (not "tuple") to list


Does someone know what's wrong with these requests ?

Is it a bad use from me or a bug or something else with PyXML ?

Thank's for your help.

With kind regards,

Gaël,