Mailman 3 February 2016 - lxml - The Python XML Toolkit

[lxml-dev] lxml has its page on launchpad
by Stefan Behnel 11 Apr '23

11 Apr '23

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

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[lxml-dev] Checking whether a node is a comment/element
by Geoffrey Sneddon 10 Apr '23

10 Apr '23

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/>

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[lxml-dev] Reparenting a node
by Lawrence Oluyede 30 Jan '23

30 Jan '23

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

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[lxml-dev] lxml 2.0.5 released
by Stefan Behnel 11 Jan '23

11 Jan '23

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.

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[lxml-dev] Building LXML Trunk
by Sidnei da Silva 31 Aug '22

31 Aug '22

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

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Building an lxml tree from C / Rust with html5ever
by Simon Sapin 25 Feb '16

25 Feb '16

Hi all, How would you recommend creating a lxml tree from C code? Or rather from Rust code, given that Rust code can call C functions and manipulate C structs, and Rust functions can be made to have a C-compatible ABI and be called from C. (I don’t mind adding some Cython code to the mix if it makes things easier.) I’ve seen http://lxml.de/capi.html and etreepublic.pxd, but it’s not clear to me if that API is suppose to be complete or if I should use libxml2’s API as well. Also, strings. Rust strings are UTF-8, and libxml2 seems to also be using UTF-8 internally. I’d rather not have everything go through Python strings and back, if possible. Any advice or links to docs or example code is appreciated. ## Background When parsing HTML in Python, there’s among others html5lib which is standards-compliant but relatively slow, and lxml.html which is very fast but uses libxml2’s old HTML 4 parser. Could we have the best of both? html5ever is a parser written for Servo per WHATWG’s HTML Standard. It’s written in Rust with performance in mind (e.g. by avoiding string copies as much as possible). The parser is separated from tree builders and tree data structures. https://github.com/servo/html5ever https://servo.org/ I’ve played a bit with using html5ever from Python through CFFI and writing tree builders in Python. Performance is somewhere in between html5lib and lxml.html. Even after some optimization, cProfile shows that more than half the time is spent in the tree builder, creating Python objects and going back and forth between languages. https://github.com/SimonSapin/html5ever-python https://github.com/SimonSapin/html5ever-python/tree/master/benchmarks I’m guessing that part of the reason lxml.html is so fast is that it doesn’t create Python object for each node during parsing, only on-demand during traversal. Perhaps a better benchmark would include a tree traversal in addition to parsing. I think the same approach could be good for html5ever-python: create libxml2 nodes in Rust / C / Cython without involving much Python code or many Python objects, and then create a lxml.etree.ElementTree object at the end. Thanks, -- Simon Sapin

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Using xinclude and XMLSchema together
by Markus Schöpflin 10 Feb '16

10 Feb '16

I'm trying to use xinclude to construct a schema which can then be parsed by XMLSchema. IOW, the following python script should print an XML document representing a valid XML schema and successfully create a XML schema object: --- include.py --- from lxml import etree tree = etree.parse("s1.xsd") tree.xinclude() print etree.tostring(tree) schema = etree.XMLSchema(tree) --- include.py --- Given the following two XML schema documents, this works as expected: --- s1.xsd --- <?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xi="http://www.w3.org/2001/XInclude"> <xi:include href="s2.xsd" xpointer="/1/1"/> </xs:schema> --- s1.xsd --- --- s2.xsd --- <?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:element name="e1"> <xs:simpleType> <xs:restriction base="xs:boolean"/> </xs:simpleType> </xs:element> <xs:element name="e2"> <xs:simpleType> <xs:restriction base="xs:boolean"/> </xs:simpleType> </xs:element> </xs:schema> --- s2.xsd --- Executing the python script gives: > python include.py <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xi="http://www.w3.org/2001/XInclude"> <xs:element xmlns:xs="http://www.w3.org/2001/XMLSchema" name="e1"> <xs:simpleType> <xs:restriction base="xs:boolean"/> </xs:simpleType> </xs:element> </xs:schema> Now for the question: How do I include *every* element defined in s2 into s1? More precisely, I want the result of 'xpath -e '/xs:schema/*' s2.xsd' to be included into s1. I have experimented with various variations of the xpointer attribute to no avail. Any help would be greatly appreciated. TIA, Markus

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lxml Windows Wheels
by John Hagen 07 Feb '16

07 Feb '16

It's been discussed before, but just wanted to ask if there had been any progress getting wheels developed for Windows. It's not possible to use lxml in virtual environments on Windows, and when lxml is a dependency of another package, the user is greeted with a cryptic pip install error. The cryptography package is a good example of wheel distribution I've seen: https://pypi.python.org/pypi/cryptography Thanks, John

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