lxml - The Python XML Toolkit March 2018

lxml@python.org

5 participants
10 discussions

[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

3 2

[lxml-dev] Checking whether a node is a comment/element
by Geoffrey Sneddon 11 Jan '23

11 Jan '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/>

4 4

[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.

3 4

[lxml-dev] lxml has its page on launchpad
by Stefan Behnel 20 Sep '22

20 Sep '22

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

3 2

[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

4 4

Re: [lxml] Difference between findall() and xpath()
by Stefan Behnel 17 Apr '18

17 Apr '18

Hi, you probably meant to reply to the list. Peng Yu schrieb am 22.03.2018 um 23:11: >> Does this help? >> >> http://lxml.de/tutorial.html#elementpath > > This does not explain their difference from `xpath()`. Can somebody be > more explicit about the differences? There are three differences. The main difference is the namespace representation: XPath uses an indirection through prefixes, ElementPath uses namespace URIs directly, thus matching the rest of the API. The second difference is that XPath has more features than ElementPath, but that's a bug. ;) And the third difference is that ElementPath supports iteration, whereas the XPath implementation always returns a complete result list. Well, and as I mentioned, ElementPath is usually faster than XPath, unless you hit a case that can structurally be expressed (and processed) more efficiently by the XPath implementation of libxml2. But that case is difficult to predict and requires proper measuring on real data. Stefan

2 1

Difference between findall() and xpath()
by Peng Yu 17 Mar '18

17 Mar '18

Hi, I am not sure what is the difference between findall() and xpath(). Could anybody show all the examples in which they are different? $ cat main.py #!/usr/bin/env python # vim: set noexpandtab tabstop=2 shiftwidth=2 softtabstop=-1 fileencoding=utf-8: from StringIO import StringIO from lxml import etree tree = etree.parse(StringIO('<foo><x><bar>abc</bar></x><bar>xyz</bar></foo>')) r = tree.xpath('/foo') print r[0].findall('bar') print r[0].xpath('bar') $ ./main.py [<Element bar at 0x102b6ce18>] [<Element bar at 0x102b6ce18>] Also, I see that findall() can be faster. Is it case that when I can use both, I should use findall() instead of xpath()? Thanks. https://blog.startifact.com/posts/older/lxml-findall-and-xpath-performance.… -- Regards, Peng

2 1

a question about formating
by Martin Mueller 17 Mar '18

17 Mar '18

In our EarlyPrint project (https://texts.earlyprint.org) my colleague has written a simple script that does two things: 1. It indents elements one space per hierarchical level 2. It arranges attributes in alphabetical order The second may be an example of what Wallace Stevens calls 'the blessed rage for order', but it has its uses since the texts go through iterative and sometimes manual editing in oXygen, and if you always encounter @lemma, @pos, and @reg in a fixed order, it's a little easier not to make mistakes. I attach the script below. It's a shell script, uses XSLT, and might be as well Chinese to me. If it were possible to integrate the script into Python or replace it with a Python function, it would make the ping-pong of exchanging iterative versions of files more orderly. From the command line you run the script as ~/format.sh A12345.xml, where A12345.xml is a filename. I understand that Python has a procedure for integrating other scripts by wrapping them in subprocess.run(). But in an lxml script the object represented by A12345 is either a tree or a serialized version in memory, and I don't know how to turn that into the argument of format.sh. Below is the script. I'll be very grateful for advice. #!/bin/sh # Sort attributes. tmp="$(mktemp)" xsltproc - "$1" > "$tmp" << STYLESHEET || { echo 'xsltproc: attribute sort failed for:' "$1" >&2; exit 1; } <?xml version="1.0"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output method="xml" encoding="UTF-8"/> <xsl:template match="*"> <xsl:copy> <xsl:apply-templates select="@*"> <xsl:sort select="name()"/> </xsl:apply-templates> <xsl:apply-templates/> </xsl:copy> </xsl:template> <xsl:template match="@*|comment()|processing-instruction()"> <xsl:copy /> </xsl:template> </xsl:stylesheet> STYLESHEET mv "$tmp" "$1" # Format with single space as the indent. tmp="$(mktemp)" XMLLINT_INDENT=$' ' xmllint --encode UTF-8 --format "$1" --output "$tmp" 2>/dev/null || { echo 'xmllint: format failed for:' "$1" >&2 exit 1 } mv "$tmp" "$1" Martin Mueller Professor emeritus of English and Classics Northwestern University

2 1

lxml 4.2.0 released
by Stefan Behnel 16 Mar '18

16 Mar '18

Hi all, I just released lxml 4.2.0 with some new features and fixes. The documentation is here: http://lxml.de/ Download: https://pypi.python.org/pypi/lxml/4.2.0 MacOS wheels are not uploaded to PyPI yet but can be expected within the next days. Changelog: http://lxml.de/4.2/changes-4.2.0.html Github: https://github.com/lxml/lxml/releases/tag/lxml-4.2.0 This release was built using Cython 0.28. If you are interested in commercial support or customisations for the lxml package, please contact me directly. Have fun, Stefan 4.2.0 (2018-03-13) ================== Features added -------------- * GH#255: ``SelectElement.value`` returns more standard-compliant and browser-like defaults for non-multi-selects. If no option is selected, the value of the first option is returned (instead of None). If multiple options are selected, the value of the last one is returned (instead of that of the first one). If no options are present (not standard- compliant) ``SelectElement.value`` still returns ``None``. * GH#261: The ``HTMLParser()`` now supports the ``huge_tree`` option. Patch by stranac. Bugs fixed ---------- * LP#1551797: Some XSLT messages were not captured by the transform error log. * LP#1737825: Crash at shutdown after an interrupted iterparse run with XMLSchema validation.

1 1

utf-8 unicode in lxml
by Peng Yu 05 Mar '18

05 Mar '18

Hi, The following example shows that utf-8 characters are not maintained. (α becomes Î±) Does anybody know how to fix the problem? Thanks. $ cat main.py #!/usr/bin/env python # vim: set noexpandtab tabstop=2 shiftwidth=2 softtabstop=-1 fileencoding=utf-8: import sys from lxml import html doc = html.parse(sys.stdin) print doc.xpath('//div')[0].text print doc.xpath('//div')[0].text_content() $ cat main.html <html> <body> <div>NT-PGC-1α</div> </body> </html> $ file main.html main.html: HTML document text, UTF-8 Unicode text $ ./main.py < main.html Î± Î± -- Regards, Peng

4 7

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

lxml - The Python XML Toolkit March 2018