Mailman 3 January 2015 - 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

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[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/>

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[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

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[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.

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[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

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Generating code from schema
by Charlie Clark Jan. 29, 2015

Jan. 29, 2015

Hi, just a quick question about what you can and cannot do with lxml's schema support. In openpyxl we're moving towards a 1:1 implementation of the underlying schema. lxml.objectify isn't directly an option for two reasons: lxml is an optional dependency and there are cases where we'd definitely run out of memory. Instead we're using descriptors to enforce type definitions. This means a little more code but now that it seems to be working well I was thinking whether we could automate some of the process. I've looked at some of the existing XSD to Python generators but the generated code is far from what I'd like to have. Can we use the lxml schema support for anything other than validation? ie. can I query a schema object for a particular definition? Or is the best approach to parse the XSD files directly and work through the definitions with a mapping? Charlie -- Charlie Clark Managing Director Clark Consulting & Research German Office Kronenstr. 27a Düsseldorf D- 40217 Tel: +49-211-600-3657 Mobile: +49-178-782-6226

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etree.xmlfile shadows exceptions thrown by output
by D.H.J. Takken Jan. 28, 2015

Jan. 28, 2015

Hello, I use etree.xmlfile and a coroutine to generate XML into a file-like object that does post-processing on the XML data. Now, if I use the send() method to produce invalid XML data, the post-processor throws an exception. Here, I see a little problem: No matter what exception is thrown by the post-processor, the send() method always generates a generic IO exception. Apparently, lxml catches any exception thrown by the file-like object and produces a generic IO exception in stead. This means that there is no way to know what exactly went wrong in the post-processor. That information is lost. Inside the coroutine, I *do* get the original exception from the post-processor, but doing the error handling there is kind of ugly. Is there a better way to solve this problem? Thanks a lot!

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moving all attributes from one element to another
by Martin Mueller Jan. 27, 2015

Jan. 27, 2015

I want to move all attributes of an element to another element. If the attributes of elements x are x.attrib and attributes = x.attrib, is there a single command that says "take the attribute dictionary of x and attach it to y"? Or do I have to use the .set method for each individual attribute? MM

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Re: [lxml] Possible bug with etree.XPath
by Alex Vincent Jan. 22, 2015

Jan. 22, 2015

> It's not about the lxml devs. The XPath compiler and engine are implemented > by libxml2 and allow you to define your own XPath functions and even > replace existing ones. Ahh, that's what I didn't know. From reading the lxml docs, behavior in libxml2 is not considered a lxml bug. That's why I came to this mailing list: for clarification. :-) Thanks, both of you! -- "The first step in confirming there is a bug in someone else's work is confirming there are no bugs in your own." -- Alexander J. Vincent, June 30, 2001

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Re: [lxml] Possible bug with etree.XPath
by Alex Vincent Jan. 22, 2015

Jan. 22, 2015

> An error will only manifest when actually evaluating the > XPath: > ... > Note that you won't run into the error when the XPath predicate's not > applied i.e. contains() is not even called: > ... > So calling with the wrong arg number is an XPath runtime, not an XPath > compile time error. > > Indeed you wouldn't know if there's an error or not at compile time: > That's what I was asking about: determining at compile time, if practical. We do our XPath lookups inside a browser, but we can read the scripts that provide the XPaths with a Python script. I understand if the lxml devs do not consider this a bug, but it would be helpful for us. I recognize your point about Python having the same behavior, except that the set of XPath 1.0 functions and their arguments are well-defined. -- "The first step in confirming there is a bug in someone else's work is confirming there are no bugs in your own." -- Alexander J. Vincent, June 30, 2001

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Possible bug with etree.XPath
by Alex Vincent Jan. 21, 2015

Jan. 21, 2015

Hi, everyone. I've been searching around for a simple XPath expression validator, just to check that the XPaths we hand-write are really valid. lxml looks like it might do well at this. However, I did find a case where an invalid expression doesn't throw: [ajvincent@localhost ~]$ python Python 2.7.8 (default, Nov 10 2014, 08:19:18) [GCC 4.9.2 20141101 (Red Hat 4.9.2-1)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> from lxml import etree >>> etree.XPath("//b[contains(.)]") //b[contains(.)] The contains function, as I understand it, takes exactly two arguments. http://www.w3.org/TR/xpath/#section-String-Functions I reproduced this with the python-lxml-3.3.6-1.fc21 package that Fedora 21 Linux provides, and on my MacBook with the py-lxml-3.4.1_0 MacPorts distribution. Please advise: is this a legitimate bug in lxml? If so, I'll file in the bug tracker. -- "The first step in confirming there is a bug in someone else's work is confirming there are no bugs in your own." -- Alexander J. Vincent, June 30, 2001

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Installation Problem
by Gabor Toth Jan. 9, 2015

Jan. 9, 2015

Dear All, I am trying to install lxml with pip on a Debian server and my tmp folder is not large enough ( I cannot increase it at the moment) and I am getting the following message, could you please suggest a workaround? Thanks, Gabor Downloading/unpacking lxml Running setup.py egg_info for package lxml /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'bugtrack_url' warnings.warn(msg) Building lxml version 3.4.1. Building without Cython. Using build configuration of libxslt 1.1.26 Building against libxml2/libxslt in the following directory: /usr/lib Installing collected packages: lxml Running setup.py install for lxml /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'bugtrack_url' warnings.warn(msg) Building lxml version 3.4.1. Building without Cython. Using build configuration of libxslt 1.1.26 Building against libxml2/libxslt in the following directory: /usr/lib building 'lxml.etree' extension gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/libxml2 -I/home/roysy/build/lxml/src/lxml/includes -I/usr/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.linux-x86_64-2.7/src/lxml/lxml.etree.o -w src/lxml/lxml.etree.c:206109:1: fatal error: error writing to /tmp/ccruZe2F.s: No space left on device compilation terminated. error: command 'gcc' failed with exit status 1 Complete output from command /usr/bin/python -c "import setuptools;__file__='/home/roysy/build/lxml/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --single-version-externally-managed --record /tmp/pip-VVbtrn-record/install-record.txt: /usr/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'bugtrack_url' warnings.warn(msg) Building lxml version 3.4.1. Building without Cython. Using build configuration of libxslt 1.1.26 Building against libxml2/libxslt in the following directory: /usr/lib running install running build running build_py copying src/lxml/includes/lxml-version.h -> build/lib.linux-x86_64-2.7/lxml/includes running build_ext building 'lxml.etree' extension gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/libxml2 -I/home/roysy/build/lxml/src/lxml/includes -I/usr/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.linux-x86_64-2.7/src/lxml/lxml.etree.o -w src/lxml/lxml.etree.c:206109:1: fatal error: error writing to /tmp/ccruZe2F.s: No space left on device compilation terminated. error: command 'gcc' failed with exit status 1 ---------------------------------------- Command /usr/bin/python -c "import setuptools;__file__='/home/roysy/build/lxml/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --single-version-externally-managed --record /tmp/pip-VVbtrn-record/install-record.txt failed with error code 1 in /home/roysy/build/lxml Storing complete log in /root/.pip/pip.log

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problem with going from linear to hierarchical structure
by Martin Mueller Jan. 9, 2015

Jan. 9, 2015

I have been struggling with what looks like a very simple problem but it is beyond my feeble powers. The longer XML fragment below is a very elaborate but flat representation of the first two lines from Shakespeare's Comedy of Errors: <sp><speaker>EGEON</speaker> <l> Proceed, Solinus, to procure my fall,</l> <l> And by the doom of death end woes and all</l> </sp> In this encoding the word, punctuation, and space tokens are not hierarchically gathered into <l> elements. Instead all such tokens are children of an <ab> element, and an empty milestone element marks the hierarchical ordering into chunks of verse or prose. Don't ask me why this somewhat counterintuitive encoding was chosen in the first place, but my goal is to "unflatten" this very flat structure, which would involve (not necessarily in that order) 1. creating an appropriate container element (<l> or <ab>) for all the tokens between one milestone and the next (or renaming the milestone element) 2 inserting all tokens between one milestone and the next into that element in their current document order 3. deleting the surrounding <ab> element The end product of these transformations would still keep the <w>, <pc>, and <c>tokens, but would have the hierarchical structure that I listed above. I see the general problem of "from linear to hierarchical," but I don't see any examples in the lxml documentation that allows me to get from here to there. It's probably a very simple thing that I should know about, but I don't, and I'll be grateful for any help. <sp xml:id="sp-0001" who="#Egeon_Err"> <speaker xml:id="spk-0001"> <w xml:id="w0000410">EGEON</w> </speaker> <ab xml:id="ab-0001"> <lb xml:id="lb-00009"/> <milestone unit="ftln" xml:id="ftln-0001" n="1.1.1" ana="#verse" corresp="#w0000420 #p0000430 #c0000440 #w0000450 #p0000460 #c0000470 #w0000480 #c0000490 #w0000500 #c0000510 #w0000520 #c0000530 #w0000540 #p0000550"/> <w xml:id="w0000420" n="1.1.1">Proceed</w> <pc xml:id="p0000430" n="1.1.1">,</pc> <c xml:id="c0000440" n="1.1.1"> </c> <w xml:id="w0000450" n="1.1.1">Solinus</w> <pc xml:id="p0000460" n="1.1.1">,</pc> <c xml:id="c0000470" n="1.1.1"> </c> <w xml:id="w0000480" n="1.1.1">to</w> <c xml:id="c0000490" n="1.1.1"> </c> <w xml:id="w0000500" n="1.1.1">procure</w> <c xml:id="c0000510" n="1.1.1"> </c> <w xml:id="w0000520" n="1.1.1">my</w> <c xml:id="c0000530" n="1.1.1"> </c> <w xml:id="w0000540" n="1.1.1">fall</w> <pc xml:id="p0000550" n="1.1.1">,</pc> <lb xml:id="lb-00010"/> <milestone unit="ftln" xml:id="ftln-0002" n="1.1.2" ana="#verse" corresp="#w0000560 #c0000570 #w0000580 #c0000590 #w0000600 #c0000610 #w0000620 #c0000630 #w0000640 #c0000650 #w0000660 #c0000670 #w0000680 #c0000690 #w0000700 #c0000710 #w0000720 #c0000730 #w0000740 #p0000750"/> <w xml:id="w0000560" n="1.1.2">And</w> <c xml:id="c0000570" n="1.1.2"> </c> <w xml:id="w0000580" n="1.1.2">by</w> <c xml:id="c0000590" n="1.1.2"> </c> <w xml:id="w0000600" n="1.1.2">the</w> <c xml:id="c0000610" n="1.1.2"> </c> <w xml:id="w0000620" n="1.1.2">doom</w> <c xml:id="c0000630" n="1.1.2"> </c> <w xml:id="w0000640" n="1.1.2">of</w> <c xml:id="c0000650" n="1.1.2"> </c> <w xml:id="w0000660" n="1.1.2">death</w> <c xml:id="c0000670" n="1.1.2"> </c> <w xml:id="w0000680" n="1.1.2">end</w> <c xml:id="c0000690" n="1.1.2"> </c> <w xml:id="w0000700" n="1.1.2">woes</w> <c xml:id="c0000710" n="1.1.2"> </c> <w xml:id="w0000720" n="1.1.2">and</w> <c xml:id="c0000730" n="1.1.2"> </c> <w xml:id="w0000740" n="1.1.2">all</w> <pc xml:id="p0000750" n="1.1.2">.</pc> </ab> </sp> Martin Mueller Professor emeritus of English and Classics Northwestern University

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XML Digital Signature (Xades)
by Ovnicraft Jan. 4, 2015

Jan. 4, 2015

Hi to all ! Maybe this topic is off, but i want to comment here and get your feedback. I am working in digital signatures for my country and i want to work just in python, so my work start reading espec about xades[1], nothing complicated, now i see lxml can help me but i want to know if anyone here has experience around this. I have an example about xml file[2] and see basic x509 cert use and RSA key. Any comment are really appreciated ! Regards ! [1] http://www.w3.org/TR/XAdES/ [2] https://gist.github.com/ovnicraft/c8645904e01e0a071199 -- [image: Cristian Salamea on about.me] Cristian Salamea about.me/ovnicraft <http://about.me/ovnicraft>

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