Mailman 3 July 2008 - lxml - The Python XML Toolkit

[lxml-dev] Does etree.iter() handle the refcount properly?
by Andrew Wang 08 Jul '08

08 Jul '08

Hi, I just started using lxml and I ran into an odd problem. I'm using version 2.0.4-14 from the OpenSuSE repositories. import lxml.etree as etree # test.py xml = '''\ <?xml version="1.0"?> <xml/>''' for i in range(10000): et = etree.fromstring(xml) for el in et.iter(): pass $ python test.py Fatal Python error: deallocating None Aborted Is this a bug, or am I using etree.iter() incorrectly? Thanks, Andrew

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[lxml-dev] validation with multiple XSD files
by Arye 07 Jul '08

07 Jul '08

Hello all, I would like to so some schema validation and started with the instructions in : http://codespeak.net/lxml/dev/validation.html#xmlschema This all works great. Now I would like to extend this to a XSD file that includes many other files. In other words I have a directory of XSD files that I would like to use. The include statement look like this (the included file is referenced by its name): <?xml version="1.0"?> <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified"> <xsd:include schemaLocation="base.xsd"/> <xsd:element name="Price"> ... ... some types defined in "base.xsd" are used here I am new to lxml so sorry in advance if the question does not make sense. Regards, Arye.

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[lxml-dev] Behaviour of Element.iter() changes when removing a node depending on whether the node has children or not
by Geoffrey Sneddon 06 Jul '08

06 Jul '08

Hi (and sorry for the stupidly long subject, but otherwise it doesn't actually cover the subject), I'm not sure whether this is a bug or not (if not, there probably ought to be some note in the docs), but, for example: >>> from lxml import etree >>> foo = etree.fromstring("<root><a><b/></a><a/></root>") >>> for element in foo.iter(etree.Element): ... print element.tag ... if element.tag == "a": ... element.getparent().remove(element) ... root a b >>> foo = etree.fromstring("<root><a/><a/></root>") >>> for element in foo.iter(etree.Element): ... print element.tag ... if element.tag == "a": ... element.getparent().remove(element) ... root a a Only in the latter case does the final a element actually appear in the iteration, whereas in the former case it just vanishes. What changes the behaviour is the fact that in former case the first a element has a child: an empty b element. -- Geoffrey Sneddon <http://gsnedders.com/>

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[lxml-dev] Removing an attribute
by Geoffrey Sneddon 05 Jul '08

05 Jul '08

Hi, I can't seem to find any way to totally remove an attribute, short of using Element.clear() (which has obvious issues when you just want to remove a single attribute). I need to remove at least @id: conformance requirements say this must be at least one character, thus just setting it to an empty string does not suffice. -- Geoffrey Sneddon <http://gsnedders.com/>

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Re: [lxml-dev] [Bug 245541] [NEW] Segfault caused by double free after GC in lxml 1.1.2
by Stefan Behnel 04 Jul '08

04 Jul '08

Hi, Mark Seaborn wrote: > I know lxml 1.1.2 is quite an old version but I wanted to > debug this segfault to find the root cause in case the root cause was > not fixed in later versions. It definitely was, likely over more than one release. > Also, the newer releases do not build on > Ubuntu edgy without upgrading lots of other components. Apparently, edgy has libxml2 2.6.26, so it should build and work. What is the problem you are experiencing? > I believe this bug is fixed in commit 44623 in version 1.3.1 (where the > description in https://codespeak.net/lxml/changes-2.0.6.html is "Better way > to prevent crashes in Element proxy cleanup code"). The respective code has been fixed and rewritten multiple times since 1.1 and IIRC the last corner cases were fixed as recent as somewhere in 2.0.x. In any case, don't use 1.3.1, as it's completely broken. I don't quite remember, that might be related to the fix or not. Stefan

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[lxml-dev] lxml segfaults
by John Morris 03 Jul '08

03 Jul '08

I'm trying to subclass lxml._Element. I'm completely new to python, so I'm definitely doing something wrong. The code below segfaults. Tried this with both lxml 1.3.6 and 2.0.7 (both from EPEL 5) along with libxslt 1.1.17 (CentOS 5 updates). Someone beat me over the head with a clue? Thanks! John Sysconf.py: -------------------- from lxml import etree class Sysconf(etree._Element): def __init__(self,datastore): etree._Element.__init__(self) test.py: -------------------- #!/usr/bin/python from lxml import etree import Sysconf sysconf = Sysconf.Sysconf("sysconf.xml") print etree.tostring(sysconf)

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[lxml-dev] Parsing XML with undefined namespace
by Andrew Stromnov 03 Jul '08

03 Jul '08

Hi, Is it possible to parse slightly broken XML like this? etree.parse("""<xml sanitizer="true" sanitizer:value="true"/>""") >>> lxml.etree.XMLSyntaxError: Namespace prefix sanitizer for value on xml is not defined, line 1, column 31 -- Andrew Stromnov

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[lxml-dev] Using the Xpath id function
by Floris Bruynooghe 02 Jul '08

02 Jul '08

Hi I've sent this to comp.lang.python a few days ago with no repsonse, so I hope you don't mind if I try here (if there is a better place please let me know)... Basically I'm trying to use the .xpath('id("foo")') method on an lxml tree but can't get it to work. Given the following XML: <root><child id="foo"/></root> And it's XMLSchema: <?xml version="1.0" encoding="UTF-8"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified"> <xs:element name="root"> <xs:complexType> <xs:sequence> <xs:element ref="child"/> </xs:sequence> </xs:complexType> </xs:element> <xs:element name="child"> <xs:complexType> <xs:attribute name="id" use="required" type="xs:ID"/> </xs:complexType> </xs:element> </xs:schema> Or in more readable, compact RelaxNG, form: element root { element child { attribute id { xsd:ID } } } Now I'm trying to parse the XML and use the .xpath() method to find the <child/> element using the id XPath function: from lxml import etree schema_root = etree.parse(file('schema.xsd')) schema = etree.XMLSchema(schema_root) parser = etree.XMLParser(schema=schema) root = etree.fromstring('<root><child id="foo"/></root>', parser) root.xpath('id("foo")') --> [] I was expecting to get the <child/> element with that last statement (well, inside a list that is), but instead I just get an empty list. Is there anything obvious I'm doing wrong? As far as I can see the lxml documentation says this should work. Cheers Floris For completeness, `dpkg -l python-lxml' tells me I'm using Debian lenny's lxml 2.0.6-1 -- Debian GNU/Linux -- The Power of Freedom www.debian.org | www.gnu.org | www.kernel.org

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[lxml-dev] 2.1beta questions: objectify.XML, objectify.parse base_url arg, deprecate enableRecursiveStr, etree.tounicode()
by Holger Joukl 02 Jul '08

02 Jul '08

Hi, I guess the module functions XML() and parse() should also support the base_url arg? Also, I suppose enableRecursiveStr() could be removed? Btw I realized that etree.tounicode() is bound to be deprecated in favor of tostring(..., encoding=unicode). I suppose this is owed to ElementTree API compat which doesn't have tounicode() - or is this a py3k issue? IMHO unicode is not an encoding and from my experience it confuses people starting out with unicode to think of unicode as an encoding. That said, I rather like the tostring()/tounicode() distinction API-wise, if purely for documentational purposes. I'm not at all questioning the possibility to produce a unicode serialization of an XML tree: This is really helpful in lxml as it enables one to fallback to python encoding capabilities if libxml2 does not support some intended target encoding. Holger -- Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger

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[lxml-dev] lxml website
by Eric Jahn 02 Jul '08

02 Jul '08

Hello folks, Just wondering if we could remove the Table of Contents sidebar shown thought the http://codespeak.net/lxml/ site. On my 12" laptop running Iceweasel/Firefox or Epiphany, it occupies most of the screen space and even flows into the main text area. I usually use Firebug to remove the "<div class="sidemenu"/> and its subelements so I can read the web page. Could we make that sidemenu resizeable or just get rid of it? Thanks! -Eric

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