Mailman 3 April 2022 - 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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Tested value modified in validation error message
by Bob Kline 15 Jul '22

15 Jul '22

Before I file a ticket, I wanted to check here to find out if this is a known problem (I searched the bug tracker, but didn't see any matches). Our customer is using a commercial XML editor and the editor's implementation of the DOM API sometimes garbles whitespace inside text nodes when serializing XML documents for the document's xml property. This causes schema validation errors when we send that serialization off to be validated against the document type's schema using lxml. The problem we have run into with lxml is that the message property of the error object which comes back in the schema object's error_log has altered the value being validated. So, for example, if the text content of an element in the serialized DOM is "Processing\ncomplete" and the value it was supposed to match in the enumerated valid values is "Processing complete" then the message attribute for the corresponding object in the error_log has Element 'ProcessingStatusValue': [facet 'enumeration'] The value 'Processing complete' is not an element of the set {'Ready for English peer review', 'Ready for English scientific review', 'Ready for English OCCM review', 'Ready for Spanish peer review', 'Ready for Spanish OCCM review', 'Ready for publishing', 'Ready for translation', 'Processing complete'}. In effect saying "the value 'Processing complete' does not match the value 'Processing complete'." Took a very long time for us to figure out that the error message was wrong, and that it should have said ... The value 'Processing\ncomplete' is not an element of the set .... -- Bob Kline https://www.rksystems.com mailto:bkline@rksystems.com

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lxml memory allocation failed
by Martin Mueller 01 May '22

01 May '22

This is about a problem I thought I had solved. I use lxml to update linguistically annotated TEI texts, where each word is wrapped in a <w> element. In a typical workflow, corrections exist as a dictionary whose key is an xmlid. The script loops through a text. If an xmlid is a dictionary key, a simple function replaces the attribute values in the <w> element. At the end of each run, the tree of the text is written to a new document. There is a final function “sort and indent” appended below, which applies some formatting to the text so that attributes appear in alphabetical and text is consistently indented. This function worked for a while, and then it started acting up. It would run through some texts but after a short interval—some times 30 seconds, sometime five minutes—it would exit with an error message like File "/users/martinmueller/Dropbox/earlyprint/eebochron/1473-1623/159/a/159-ane-A21328.xml", line 27 lxml.etree.XMLSyntaxError: Memory allocation failed, line 27, column 19 If you started the run again from the file on which it had exited, it would process that file properly but stumble again some files later. If you remove the function the error disappears. Which supports two conclusions: 1. The error has something to do with that function 2. It has nothing to do with the way it handles any individual text When I reported that problem at an earlier time, I think that Stefan advised me to introduce some step that would clear memory after each single text. I remember that this didn’t work and I gave up on that function, thinking that perhaps there was some problem with the way in which Python, Anaconda and lxml interacted. Recently I got rid of Anaconda and updated to the latest versions of Python and lxml. The problem disappeared for a little while, but then it reappeared. So I tried again two ways of clearing memory. I add either “tree=’None’” or “del tree” as the last command for any given file. This made no difference. The most plausible explanation for this behaviour is that there is some cumulative effect which aborts the program when it causes some threshold. The way I reset doesn’t work. Oddly enough, while I have been writing this email, the script has run through 343 texts in 645 seconds and is still chugging away. One of the texts is very long, from which I gather that the cumulative length of texts processed between failures is unlikely to be the cause of failure. It finally failed after 400 texts and 721 second. The next run failed after 44 texts and 41 seconds. The error message refers to an lxml.etree.XMLSyntaxError. I looked up some failure points in particular text, but couldn’t see any pattern. Besides, the point of failure is never a point of failure the second time round. The problem must have something to do with the little function below. If you drop, lxml will process thousands or tens of thousands of text without any problem of building one tree, doing stuff with it, and dropping it for another tree. But what is it about this code that will work perfectly on any individual text but has cumulative effect that typically leads to failure a after two or three dozen texts. def sort_and_indent(elem, level: int = 0): attrib = elem.attrib if len(attrib) > 1: attributes = sorted(attrib.items()) attrib.clear() attrib.update(attributes) i = "\n" + " " * level if len(elem): if not elem.text or not elem.text.strip(): elem.text = i + " " if not elem.tail or not elem.tail.strip(): elem.tail = i for elem in elem: sort_and_indent(elem, level + 1) if not elem.tail or not elem.tail.strip(): elem.tail = i else: if level and (not elem.tail or not elem.tail.strip()): elem.tail = i

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