Mailman 3 May 2010 - lxml - The Python XML Toolkit

[lxml-dev] lxml has its page on launchpad
by Stefan Behnel April 11, 2023

April 11, 2023

Hi all, I added the lxml project to launchpad, the Ubuntu Bug-Tracker. It also has a FAQ engine and a couple of other goodies. https://launchpad.net/lxml It's easy to sign up for launchpad, BTW, no 90%-footnotes-contract. Have fun, Stefan

9 9

[lxml-dev] Checking whether a node is a comment/element
by Geoffrey Sneddon April 10, 2023

April 10, 2023

Hi, What's the best way to check whether a given node is a comment or an element? For the former, I'm currently using isinstance(node, etree._Comment), which is rather obviously sub-optimal. -- Geoffrey Sneddon <http://gsnedders.com/>

6 6

[lxml-dev] Reparenting a node
by Lawrence Oluyede Jan. 30, 2023

Jan. 30, 2023

I have a doc A and a doc B, I'd like to put a node extracted from A in the document B but I always get a ValueError: ValueError: Element is not a child of this node. I didn't find any "setparent" in the API. How can I do this? -- Lawrence, oluyede.org - neropercaso.it "It is difficult to get a man to understand something when his salary depends on not understanding it" - Upton Sinclair

3 2

[lxml-dev] lxml 2.0.5 released
by Stefan Behnel Jan. 11, 2023

Jan. 11, 2023

Hi all, lxml 2.0.5 is on PyPI. This is a bug-fix-only release of the stable 2.0 series. Have fun, Stefan 2.0.5 (2008-05-01) Bugs fixed * Resolving to a filename in custom resolvers didn't work. * lxml did not honour libxslt's second error state "STOPPED", which let some XSLT errors pass silently. * Memory leak in Schematron with libxml2 >= 2.6.31.

3 4

[lxml-dev] Building LXML Trunk
by Sidnei da Silva Aug. 31, 2022

Aug. 31, 2022

Hi, I've tried to build lxml from trunk today, on Win32. Got the following error: src\lxml\etree.c(880) : error C2059: syntax error : ')' src\lxml\etree.c(881) : error C2059: syntax error : ')' src\lxml\etree.c(882) : error C2059: syntax error : ')' src\lxml\etree.c(883) : error C2059: syntax error : ')' Any clue? Smells like a Pyrex issue? -- Sidnei da Silva Enfold Systems http://enfoldsystems.com Fax +1 832 201 8856 Office +1 713 942 2377 Ext 214

4 4

[lxml-dev] confusing xpath performance characteristics
by jholg＠gmx.de Aug. 24, 2012

Aug. 24, 2012

Hi, I ran into some performance characteristics of lxml/libxml2 xpath that I find rather confusing: I try to find the @type attribute of a certain element in an XML Schema (which contains lots of complexType definitions with lots of elements in them; unfortunately I can't post the schema): >>> timeit.Timer(stmt="""xpath(schema)""", setup="""from lxml import etree, objectify; schema=etree.parse('NDM.xsd').getroot(); xpath = etree.XPath('//xs:element[@name="equity"]/@type', namespaces={'xs': 'http://www.w3.org/2001/XMLSchema'})""").repeat(number=10) [0.095885038375854492, 0.096823930740356445, 0.096174955368041992] So I think I'm being smart and give a little more path information - reckoning that this should *improve* performance: >>> timeit.Timer(stmt="""xpath(schema)""", setup="""from lxml import etree, objectify; schema=etree.parse('NDM.xsd').getroot(); xpath = etree.XPath('/xs:schema//xs:element[@name="equity"]/@type', namespaces={'xs': 'http://www.w3.org/2001/XMLSchema'})""").repeat(number=10) [0.1770780086517334, 0.1775970458984375, 0.17748594284057617] Hm. Performance degrades slightly. I'm adding even more of the path to where my desired elements live in the schema: >>> timeit.Timer(stmt="""xpath(schema)""", setup="""from lxml import etree, objectify; schema=etree.parse('xsd/NDM.xsd').getroot(); xpath = etree.XPath('/xs:schema/xs:complexType//xs:element[@name="equity"]/@type', namespaces={'xs': 'http://www.w3.org/2001/XMLSchema'})""").repeat(number=10) [103.79744100570679, 103.83671712875366, 103.61817717552185] What??? >>> timeit.Timer(stmt="""xpath(schema)""", setup="""from lxml import etree, objectify; schema=etree.parse('/ae/data/pydev/hjoukl/NDM/SVN_CO/TRUNK/ndm/reference/xsd/NDM.xsd').getroot(); xpath = etree.XPath('/xs:schema/xs:complexType/*/xs:element[@name="equity"]/@type', namespaces={'xs': 'http://www.w3.org/2001/XMLSchema'})""").repeat(number=10) [0.044407129287719727, 0.044126987457275391, 0.044229030609130859] >>> Ok, this version's better than my naive approach, which seems logical to me. But why would '/xs:schema/xs:complexType//xs:element[@name="equity"]/@type' perform drastically slower than '/xs:schema/xs:complexType//xs:element[@name="equity"]/@type' ? libxml2 problem? Running the same xpaths in Oxygen I don't notice performance differences (can't profile this). Holger -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

2 5

[lxml-dev] Relax NG validation question
by Fred Drake June 28, 2010

June 28, 2010

I've been using jing to validate documents against a schema written in the RelaxNG compact syntax. I'd like to use lxml to validate instead of using jing. After converting the schema to the XML syntax using trang, I'm loading the schema like so: >>> import lxml.etree >>> doc = lxml.etree.parse("top.rng") >>> schema = lxml.etree.RelaxNG(doc) Traceback (most recent call last): File "<console>", line 1, in <module> File "relaxng.pxi", line 84, in lxml.etree.RelaxNG.__init__ (src/lxml/lxml.etree.c:114962) RelaxNGParseError: xmlRelaxNG: include middle.rng has a define anyElement but not the included grammar, line 9 I suspect something about the include structure of my schema is causing lxml this heartburn. I've reproduced this with a cut-down version of the schema, but I'm using the same include structure as the original, since I suspect that's essential (and I'd like to retain that instead of restructuring the actual schema). My schema is written as three files (attached): base.rng This is really just a very-slightly-modified copy of the Atom schema. It defines an "anyElement" pattern. This can be loaded on it's own. middle.rng This includes and extends base.rng. It makes no specific mention of the "anyElement" pattern. This can be loaded on it's own. top.rng This is the top-level schema that I actually care about validating; it overrides the "anyElement" pattern as part of the include of middle.rng. Building the RelaxNG object from this document causes the exception shown above. Any ideas? I'm using Python 2.6.5 and lxml 2.2.6, libxml2 2.7.7, and libxslt 1.1.26. -Fred -- Fred L. Drake, Jr. <fdrake at gmail.com> "Chaos is the score upon which reality is written." --Henry Miller

2 2

[lxml-dev] Force element content to be string
by Sebastian Rahlf June 9, 2010

June 9, 2010

Hi all! I have a bit of XML which I want to parse via lxml.objectify. from lxml import objectify node = objectify.fromstring(''' <Item> <ASIN>0747532745</ASIN> <ItemAttributes> <Author>Joanne K. Rowling</Author> <Manufacturer>Bloomsbury Publishing</Manufacturer> <ProductGroup>Book</ProductGroup> <Title>Harry Potter and the Philosopher's Stone</Title> </ItemAttributes> </Item> ''') I have the following problem: node.ASIN is evaluated to integer value 747532745 but should be a string ('0747532745'). There is no way for me to influence the incoming XML, so any py:pytype magic or adding a schema is out of the question. Is there a way to ensure that ASIN elements are always evaluated to a string? Cheers, Seb. -- Sebastian Rahlf basti(a)redtoad.de

2 3

[lxml-dev] Failure to open http urls on Windows
by Laurence Rowe May 26, 2010

May 26, 2010

Hi, I'm seeing an IOError when resolving http urls on Windows (it works fine on Mac OS X): >>> from lxml import etree >>> etree.parse('http://codespeak.net/', parser=etree.HTMLParser()) Traceback (most recent call last): File "<console>", line 1, in ? File "lxml.etree.pyx", line 2706, in lxml.etree.parse (src/lxml/lxml.etree.c:49958) File "parser.pxi", line 1500, in lxml.etree._parseDocument (src/lxml/lxml.etree.c:71797) File "parser.pxi", line 1529, in lxml.etree._parseDocumentFromURL (src/lxml/lxml.etree.c:72080) File "parser.pxi", line 1429, in lxml.etree._parseDocFromFile (src/lxml/lxml.etree.c:71175) File "parser.pxi", line 975, in lxml.etree._BaseParser._parseDocFromFile (src/lxml/lxml.etree.c:68173) File "parser.pxi", line 539, in lxml.etree._ParserContext._handleParseResultDoc (src/lxml/lxml.etree.c:64257) File "parser.pxi", line 625, in lxml.etree._handleParseResult (src/lxml/lxml.etree.c:65178) File "parser.pxi", line 563, in lxml.etree._raiseParseError (src/lxml/lxml.etree.c:64493) IOError: Error reading file 'http://codespeak.net/': failed to load external entity "http://codespeak.net/"

4 5

Re: [lxml-dev] Can't get lxml to work with Python 3 (installation with errors, importing works, usage doesn't)
by codethief May 26, 2010

May 26, 2010

> Ok, so I misinterpreted the error trace. The respective code in lxml.etree > needs to be somewhat flexible and ended up a bit too fragile. So, if you > pass a "non-standard" file-like object, it might end up raising an exception > like this. > > Here's a fix. Take care to use Cython 0.12.1 when you build from patched > lxml 2.2.x sources. Thanks for the fix! I'm apparently too dumb to apply the .diff using patch (there was always some strange error occuring), so I patched apihelpers.pxi manually. :D When building the patched 2.2.6 sources, which I downloaded from http://pypi.python.org/packages/source/l/lxml/lxml-2.2.6.tar.gz), using Cython 0.12.1 I receive the following error: ---- $ python3 setup.py bdist_egg [...] gcc -pthread -fno-strict-aliasing -DNDEBUG -g -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/libxml2 -I/usr/include/python3.1 -c src/lxml/lxml.etree.c -o build/temp.linux-x86_64-3.1/src/lxml/lxml.etree.o -w gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions build/temp.linux-x86_64-3.1/src/lxml/lxml.etree.o -lxslt -lexslt -lxml2 -lz -lm -o build/lib.linux-x86_64-3.1/lxml/etree.so building 'lxml.objectify' extension gcc -pthread -fno-strict-aliasing -DNDEBUG -g -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/libxml2 -I/usr/include/python3.1 -c src/lxml/lxml.objectify.c -o build/temp.linux-x86_64-3.1/src/lxml/lxml.objectify.o -w src/lxml/lxml.objectify.c:573: error: conflicting types for ‘__Pyx_ImportType’ src/lxml/lxml.etree_api.h:160: note: previous definition of ‘__Pyx_ImportType’ was here error: command 'gcc' failed with exit status 1 ---- I tried the same with the newest SVN sources (lxml 2.3 r74722) and it worked (both, building and the bugfix). For anyone who cares I uploaded the egg: It's available on http://codethief.eu/kram/_/lxml-2.3dev-py3.1-linux-x86_64.egg P.S. Any plans to migrate to a distributed revision control system like Git or preferably (in my opinion) Mercurial? That'd make many things a lot easier. Just take github.com and bitbucket.org which expose a much nicer user interface than SVN does. :) -- Simon Hirscher http://simonhirscher.de

2 1