lxml - The Python XML Toolkit January 2009

lxml@python.org

21 participants
30 discussions

[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/>

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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] lxml has its page on launchpad
by Stefan Behnel 21 Sep '22

21 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

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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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[lxml-dev] Compilation of lxml on Windows 64-bit
by Hanni Ali 17 Jul '09

17 Jul '09

Hi All, Came across this little gem of a Python module which seems able to translate some XML reports for me nicely. I was very pleased to see a Python 2.6 installer for windows, made checking it out much easier than many modules I use. So thanks for that. However although my testing seems to confirm this is the ideal module I do need to deploy to our production environment which is a 64-bit Windows environment running Python 2.6 (I code on 32-bit box for simplicity/resource reasons). Has anyone compiled and used lxml on this platform combination? If not does anyone foresee me having any issues compiling it for this platform? Thanks, Hanni

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[lxml-dev] Standalone declaration
by Ovnicraft 26 Feb '09

26 Feb '09

Hi, i am new with lxml and is great, i created an xml now i want to make standalone declaration in my structure, how i can do it? i search in docs but i didnt good results. Thx in advance -- [b]question = (to) ? be : !be; .[/b]

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Re: [lxml-dev] Unable to solve a crash on Windows with LXML
by Stefan Behnel 06 Feb '09

06 Feb '09

Hi, I'm CC-ing the list, I hope you don't mind. I think your description is abstract enough not to reveal anything about your application. Robert Liebeskind wrote: > The trace you received was from v2.2 of lxml but we continue to > experience > the same issue with v2.5. We use XPath extensively. We do not use > XSLT. I guess you meant 2.2beta1 and 2.1.5? > 1. An etree is loaded from an xml file and the data displayed for the > user. > 2. The etree is modified as the result of user edits using a GUI I assume that this happens inside one thread. > 3. The etree is the copied using copy.deepcopy() to etree2 > 4. etree2 is passed via a queue to a thread in which it is further > processed. Try copying the tree inside the target thread, (preferably) instead of copying it inside another thread and passing it over. Trees inherit state from the thread that built them. Also, using a tree inside a thread that did not build it will result in some additional adaptation overhead. > 5. etree2 is modfied as a result of processing in its own thread. > during this processing > additional trees/elems are fetched from disk and used to modify/ > augment etree2. > 6. etree2 is copied to etree3 > 7. etree3 is sent for a additional processing in its own thread. > 8. etree2 is copied to etree4 > 9. etree 4 is sent for additional processing in its own thread. Same thing for 6/7 and 8/9. Copying the tree from inside the target thread will make things more stable. Even if multiple copying is not really memory friendly, it's very fast in lxml, so as long as we are not talking about documents with several megabytes, and as long as this thing really runs on a multi processor machine, you should be fine even with a work-around that copies the tree redundantly in both threads. > at this point the initial thread is complete and tears down. > the two additional spawned threads finish quickly and tear down as well. > These processes will succeed quite often. They fail intermittently > and result in a Windows Unhandled Exception. lxml.etree uses a per-thread dictionary that holds names of tags and attributes. That's one of the reasons why it's so fast and memory friendly. In the stack trace you showed me, it seems that a tree is freed in a different thread than the one that built it, but (for whatever reason) some of it content is still linked to a dictionary of the original thread. In this case, the tree cleanup cannot detect that the name is stored in a dictionary and will free it manually. When the originating thread goes down, either before or after the thread that freed the tree, it will destroy the dictionary that stores the name, which results in a double free. Does that help for now? Stefan

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[lxml-dev] Avoiding re-parsing for document loading
by Laurence Rowe 30 Jan '09

30 Jan '09

I have an XSLT that accesses a number of other documents. These other documents are also created in lxml. Is there a way to pass them to my stylesheet without incurring an additional parse? Laurence

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[lxml-dev] Serialization to file does not report error
by Frédéric Mantegazza 29 Jan '09

29 Jan '09

I use the following code to serialize a tree to a file: tree.write(self.__fileName, pretty_print=True, xml_declaration=True) if the file pointed by self.__fileName is not writable (not owned by the current user), the call silently exits, but the file is not written. I have to use: file_ = file(self.__fileName, 'w') tree.write(file_, pretty_print=True, xml_declaration=True) file_.close() to catch en exception in this case. I'm using lxml 1.1.1; this is an old version (from debian etch), and it might have been corrected in new release... -- Frédéric

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[lxml-dev] lxml is not built against the libxml2 it says it is
by Ian Kallen 29 Jan '09

29 Jan '09

I've got some intermittent lxml problems (long stalls and memory bloats) that are difficult to isolate. Ahead of the whole valgrind route, I wanted to install the latest, greatest code. So I have these in /usr/local/lib * libxml2-2.6.32 * libxslt-1.1.24 I cannot uninstall the libxml2 that came with the system (libxml2-2.6.26) because the system's yum and autofs installations depend on it. When try building lxml, I see this reassuring messages Building against libxml2/libxslt in the following directory: /usr/local/lib Yet, after the installation it's linked against the system one in /usr ldd /usr/local/lib/python2.5/site-packages/lxml-2.1.5-py2.5-linux-i686.egg/lxml/etree.so linux-gate.so.1 => (0x00a9e000) libxslt.so.1 => /usr/lib/libxslt.so.1 (0x0056f000) libexslt.so.0 => /usr/lib/libexslt.so.0 (0x00dbd000) libxml2.so.2 => /usr/lib/libxml2.so.2 (0x00ba5000) libz.so.1 => /usr/lib/libz.so.1 (0x00dec000) libm.so.6 => /lib/libm.so.6 (0x002cf000) libpython2.5.so.1.0 => /usr/local/lib/libpython2.5.so.1.0 (0x002f6000) libpthread.so.0 => /lib/libpthread.so.0 (0x00fd8000) libc.so.6 => /lib/libc.so.6 (0x0042a000) libgcrypt.so.11 => /usr/lib/libgcrypt.so.11 (0x00835000) libgpg-error.so.0 => /usr/lib/libgpg-error.so.0 (0x00aba000) libdl.so.2 => /lib/libdl.so.2 (0x0023a000) /lib/ld-linux.so.2 (0x00f35000) libutil.so.1 => /lib/libutil.so.1 (0x0023e000) libnsl.so.1 => /lib/libnsl.so.1 (0x00242000) This is with lxml-2.1.5 (also using Cython-0.10.3, if that's relevant). How do I force lxml to link against the libxml2 in /usr/local ? thanks, -Ian

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lxml - The Python XML Toolkit January 2009