Mailman 3 December 2017 - lxml - The Python XML Toolkit

[lxml-dev] lxml has its page on launchpad
by Stefan Behnel 10 Apr '23

10 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 09 Apr '23

09 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 30 Aug '22

30 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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docinfo.doctype don't return the original doctype
by Kim Grønborg Nielsen 28 Dec '17

28 Dec '17

I’m using following code to extract DOCTYPE with python 2.7 and lxml 4.1.1: from lxml import tree from StringIO import StringIO if __name__ == '__main__': doc = etree.parse(StringIO('''<?xml version="1.0"?> <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd"> <log4j:configuration xmlns:log4j = "http://jakarta.apache.org/log4j/" debug="false"> <a>tasty</a> </log4j:configuration>''')) print "Type: {}\n".format(doc.docinfo.doctype) But it returns: Type: <!DOCTYPE configuration SYSTEM "log4j.dtd”> And not, as I expected: Type: <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd"> Is it a bug in lxml? Is there a workaround for getting what I’m expecting? =:-) Kim Grønborg Nielsen M kgn+lxml(a)network-it.dk

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lxml.objectify with xml elements containing hyphens ('-')
by Grazhdani Jonian 27 Dec '17

27 Dec '17

Hello, We have been using lxml.objectify for a while for our xml work in python and I really appreciate its neat way of converting xml Elements to python objects and vice-versa. That worked great until we needed to add support for an xml-based standard which extensively uses hyphens in its element names (Specifically the MDX from ASAM https://www.asam.net/standards/detail/mdx/wiki/ ). The resulting lxml.objectify objects have a lot of attributes with hyphens which makes their use in python very cumbersome, since using hyphens in variable names in forbidden in python and results in a syntax error. Googling pointed me to use getattr() / setattr() instead of the dot notation, which I have done, also in combination with xpath expressions to avoid ridiculous getattr() chains. It does do the job but the resulting code is a nightmare to work with and maintain (See example code as post scriptum below). I kindly ask those of you who have extensive experience with hyphened elements to provide me some guidance on what would be the best way to proceed from here. The alternatives I see in front of me are: 1 Convert all element names to use another character (e.g. underscore) instead of hyphen before objectify parsing, and then converting back before exporting. 2 Continue with getattr() / setattr() 3 give up objectify Obviously (and unfortunately) changing the standard is not an option. If you have any other approaches not listed above I would be very happy if you could share them with me! I am seriously considering giving alternative 1 a try and figured out I would need to convert both the schema and the xml to make objectify work. Any tips on doing that in a smart way would be also welcome. Happy holidays and thank you for your help! Jonian Grazhdani EMS Software Architect Powertrain Control System Development Scania CV AB SE-151 87 Södertälje, Sweden tel: +46 (0)8 553 53427 e-mail: jonian.grazhdani(a)scania.com<mailto:jonian.grazhdani@scania.com> P.S. Example code with two implementations: NAMESPACE = "http://www.asam.net/schema/MDX/r1.3" E = objectify.ElementMaker(annotate=False, namespace=NAMESPACE, nsmap={ None: NAMESPACE, 'xsd': 'http://www.w3.org/2001/XMLSchema', 'xsi': 'http://www.w3.org/2001/XMLSchema-instance'}) # Implementation 1: dot notation which results in a syntax error self.sw_feature = E.SW-FEATURE( E.SHORT-NAME(self.short_name), E.CATEGORY("FCT"), E.SW-FEATURE-OWNED-ELEMENT-SETS( E.SW-FEATURE-OWNED-ELEMENT-SET( E.SW-FEATURE-ELEMENTS() ), E.SW-FEATURE-INTERFACES(), ID = self.id ) if len(self.owned_elements['SW-VARIABLE-REFS']) > 0: self.sw_feature.SW-FEATURE-OWNED-ELEMENT-SETS.SW-FEATURE-OWNED-ELEMENT-SET.SW-FEATURE-ELEMENTS.SW-VARIABLE-REFS = E.SW-VARIABLE-REFS() self.sw_feature.SW-FEATURE-OWNED-ELEMENT-SETS.SW-FEATURE-OWNED-ELEMENT-SET.SW-FEATURE-ELEMENTS.SW-VARIABLE-REFS = self.owned_elements['SW-VARIABLE-REFS'] # Implementation 2: getattr / setattr with the occasional xpath self.sw_feature = getattr(E,'SW-FEATURE')( getattr(E,'SHORT-NAME')(self.short_name), E.CATEGORY("FCT"), getattr(E,'SW-FEATURE-OWNED-ELEMENT-SETS')( getattr(E,'SW-FEATURE-OWNED-ELEMENT-SET')( getattr(E,'SW-FEATURE-ELEMENTS')() ) ), getattr(E,'SW-FEATURE-INTERFACES')(), ID = self.id ) mdx_sw_feature_elements = self.sw_feature.find("./{ns}SW-FEATURE-OWNED-ELEMENT-SETS/{ns}SW-FEATURE-OWNED-ELEMENT-SET/{ns}SW-FEATURE-ELEMENTS".format(ns="{" + NAMESPACE + "}")) if self.owned_elements['SW-VARIABLE-REFS']: setattr(mdx_sw_feature_elements, 'SW-VARIABLE-REFS', getattr(E, 'SW-VARIABLE-REFS')()) mdx_sw_refs = getattr(mdx_sw_feature_elements, 'SW-VARIABLE-REFS') #set the objects children (e.g. SW-VARIABLE-REFS.SW-VARIABLE-REF) setattr('SW-VARIABLE-REFS', 'SW-VARIABLE-REF', self.owned_elements['SW-VARIABLE-REFS'])

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What is the difference between XML() and fromstring() in etree?
by Peng Yu 20 Dec '17

20 Dec '17

I am trying to find out the difference between XML() and fromstring() in etree. But it seems that they are the same. Does anybody know if what is the main difference between them? Thanks. $ cat ./main.py #!/usr/bin/env python # vim: set noexpandtab tabstop=2 shiftwidth=2 softtabstop=-1 fileencoding=utf-8: from lxml import etree tree = etree.fromstring('<a>text</a>') print type(tree) tree = etree.XML('<a>text</a>') print type(tree) $ ./main.py <type 'lxml.etree._Element'> <type 'lxml.etree._Element'> Help on cython_function_or_method in module lxml.etree: XML(...) XML(text, parser=None, base_url=None) Parses an XML document or fragment from a string constant. Returns the root node (or the result returned by a parser target). This function can be used to embed "XML literals" in Python code, like in >>> root = XML("<root><test/></root>") >>> print(root.tag) root To override the parser with a different ``XMLParser`` you can pass it to the ``parser`` keyword argument. The ``base_url`` keyword argument allows to set the original base URL of the document to support relative Paths when looking up external entities (DTD, XInclude, ...). Help on cython_function_or_method in module lxml.etree: fromstring(...) fromstring(text, parser=None, base_url=None) Parses an XML document or fragment from a string. Returns the root node (or the result returned by a parser target). To override the default parser with a different parser you can pass it to the ``parser`` keyword argument. The ``base_url`` keyword argument allows to set the original base URL of the document to support relative Paths when looking up external entities (DTD, XInclude, ...). -- Regards, Peng

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What is the difference between etree.XML and etree.HTML?
by Peng Yu 20 Dec '17

20 Dec '17

Hi, In the following example, XML and HTML work equally well. Does anybody has an example showing when they will be different? Thanks. from lxml import etree tree = etree.XML('<foo><bar>abc</bar></foo>') tree = etree.HTML('<foo><bar>abc</bar></foo>') print type(tree) r = tree.xpath('//bar') print [x.tag for x in r] -- Regards, Peng

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Which version of xpath does lxml support?
by Peng Yu 19 Dec '17

19 Dec '17

Hi, I don't find this in the document. Maybe I miss it? Does lxml support xpath version 1 or 2? Thanks. -- Regards, Peng

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