lxml - The Python XML Toolkit August 2008

lxml@python.org

25 participants
39 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

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[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] lxml 2.0 beta1 released
by Stefan Behnel 22 Dec '08

22 Dec '08

Hi all, I finally managed to push lxml 2.0beta1 over to PyPI. This release marks the end of the four month alpha cycle of lxml 2.0. The last stable release series, lxml 1.3, saw the light of day more than six months ago. http://codespeak.net/lxml/dev/ http://pypi.python.org/pypi/lxml/2.0beta1 The complete changelog for beta1 and the 2.0 alpha series follows below. Apart from a number of important fixes and enhancements, this beta release also finalises the major API changes that make the difference between 1.x and 2.x. Incompatible changes after this release will require a very good motivation. As usual, compatible enhancements will always be embraced - as will be updates, clarifications and fixes for the documentation! Asking back helps. I expect beta1 to also be the last beta release before lxml 2.0 final (hopefully not in the sense that alpha4/5/6 were), so please test as much as you can to spot any remaining bugs and problems. Note that this release depends on a bug fix in Cython that will hopefully be released as Cython 0.9.6.11 in a couple of days. I attached the necessary patch for those who want work on the sources. Another thing: there was a security advisory on the libxml2 mailing list. To prevent DoS attacks, systems that parse XML from untrusted sources should be updated to libxml2 2.6.31 (or should apply the patch that is referenced in Daniel's post below). http://mail.gnome.org/archives/xml/2008-January/msg00036.html Sidnei, when you build the Windows binaries, could you please wait for libxml2 2.6.31 to become available as binaries as well? Hopefully, that won't take too long... Have fun, Stefan 2.0beta1 (2008-01-11) ===================== Features added -------------- * Parse-time XML schema validation (``schema`` parser keyword). * XPath string results of the ``text()`` function and attribute selection make their Element container accessible through a ``getparent()`` method. As a side-effect, they are now always unicode objects (even ASCII strings). * ``XSLT`` objects are usable in any thread - at the cost of a deep copy if they were not created in that thread. * Invalid entity names and character references will be rejected by the ``Entity()`` factory. * ``entity.text`` returns the textual representation of the entity, e.g. ``&``. Bugs fixed ---------- * XPath on ElementTrees could crash when selecting the virtual root node of the ElementTree. * Compilation ``--without-threading`` was buggy in alpha5/6. Other changes ------------- * Minor performance tweaks for Element instantiation and subelement creation 2.0alpha6 (2007-12-19) ====================== Features added -------------- * New properties ``position`` and ``code`` on ParseError exception (as in ET 1.3) Bugs fixed ---------- * Memory leak in the ``parse()`` function. * Minor bugs in XSLT error message formatting. * Result document memory leak in target parser. Other changes ------------- * Various places in the XPath, XSLT and iteration APIs now require keyword-only arguments. * The argument order in ``element.itersiblings()`` was changed to match the order used in all other iteration methods. The second argument ('preceding') is now a keyword-only argument. * The ``getiterator()`` method on Elements and ElementTrees was reverted to return an iterator as it did in lxml 1.x. The ET API specification allows it to return either a sequence or an iterator, and it traditionally returned a sequence in ET and an iterator in lxml. However, it is now deprecated in favour of the ``iter()`` method, which should be used in new code wherever possible. * The 'pretty printed' serialisation of ElementTree objects now inserts newlines at the root level between processing instructions, comments and the root tag. * A 'pretty printed' serialisation is now terminated with a newline. * Second argument to ``lxml.etree.Extension()`` helper is no longer required, third argument is now a keyword-only argument ``ns``. * ``lxml.html.tostring`` takes an ``encoding`` argument. 2.0alpha5 (2007-11-24) ====================== Features added -------------- * Rich comparison of ``element.attrib`` proxies. * ElementTree compatible TreeBuilder class. * Use default prefixes for some common XML namespaces. * ``lxml.html.clean.Cleaner`` now allows for a ``host_whitelist``, and two overridable methods: ``allow_embedded_url(el, url)`` and the more general ``allow_element(el)``. * Extended slicing of Elements as in ``element[1:-1:2]``, both in etree and in objectify * Resolvers can now provide a ``base_url`` keyword argument when resolving a document as string data. * When using ``lxml.doctestcompare`` you can give the doctest option ``NOPARSE_MARKUP`` (like ``# doctest: +NOPARSE_MARKUP``) to suppress the special checking for one test. Bugs fixed ---------- * Target parser failed to report comments. * In the ``lxml.html`` ``iter_links`` method, links in ``<object>`` tags weren't recognized. (Note: plugin-specific link parameters still aren't recognized.) Also, the ``<embed>`` tag, though not standard, is now included in ``lxml.html.defs.special_inline_tags``. * Using custom resolvers on XSLT stylesheets parsed from a string could request ill-formed URLs. * With ``lxml.doctestcompare`` if you do ``<tag xmlns="...">`` in your output, it will then be namespace-neutral (before the ellipsis was treated as a real namespace). Other changes ------------- * The module source files were renamed to "lxml.*.pyx", such as "lxml.etree.pyx". This was changed for consistency with the way Pyrex commonly handles package imports. The main effect is that classes now know about their fully qualified class name, including the package name of their module. * Keyword-only arguments in some API functions, especially in the parsers and serialisers. 2.0alpha4 (2007-10-07) ====================== Features added -------------- Bugs fixed ---------- * AttributeError in feed parser on parse errors Other changes ------------- * Tag name validation in lxml.etree (and lxml.html) now distinguishes between HTML tags and XML tags based on the parser that was used to parse or create them. HTML tags no longer reject any non-ASCII characters in tag names but only spaces and the special characters ``<>&/"'``. 2.0alpha3 (2007-09-26) ====================== Features added -------------- * Separate ``feed_error_log`` property for the feed parser interface. The normal parser interface and ``iterparse`` continue to use ``error_log``. * The normal parsers and the feed parser interface are now separated and can be used concurrently on the same parser instance. * ``fromstringlist()`` and ``tostringlist()`` functions as in ElementTree 1.3 * ``iterparse()`` accepts an ``html`` boolean keyword argument for parsing with the HTML parser (note that this interface may be subject to change) * Parsers accept an ``encoding`` keyword argument that overrides the encoding of the parsed documents. * New C-API function ``hasChild()`` to test for children * ``annotate()`` function in objectify can annotate with Python types and XSI types in one step. Accompanied by ``xsiannotate()`` and ``pyannotate()``. Bugs fixed ---------- * XML feed parser setup problem * Type annotation for unicode strings in ``DataElement()`` Other changes ------------- * lxml.etree now emits a warning if you use XPath with libxml2 2.6.27 (which can crash on certain XPath errors) * Type annotation in objectify now preserves the already annotated type by default to prevent loosing type information that is already there. 2.0alpha2 (2007-09-15) ====================== Features added -------------- * ``ET.write()``, ``tostring()`` and ``tounicode()`` now accept a keyword argument ``method`` that can be one of 'xml' (or None), 'html' or 'text' to serialise as XML, HTML or plain text content. * ``iterfind()`` method on Elements returns an iterator equivalent to ``findall()`` * ``itertext()`` method on Elements * Setting a QName object as value of the .text property or as an attribute will resolve its prefix in the respective context * ElementTree-like parser target interface as described in http://effbot.org/elementtree/elementtree-xmlparser.htm * ElementTree-like feed parser interface on XMLParser and HTMLParser (``feed()`` and ``close()`` methods) Bugs fixed ---------- * lxml failed to serialise namespace declarations of elements other than the root node of a tree * Race condition in XSLT where the resolver context leaked between concurrent XSLT calls Other changes ------------- * ``element.getiterator()`` returns a list, use ``element.iter()`` to retrieve an iterator (ElementTree 1.3 compatible behaviour) 2.0alpha1 (2007-09-02) ====================== Features added -------------- * Reimplemented ``objectify.E`` for better performance and improved integration with objectify. Provides extended type support based on registered PyTypes. * XSLT objects now support deep copying * New ``makeSubElement()`` C-API function that allows creating a new subelement straight with text, tail and attributes. * XPath extension functions can now access the current context node (``context.context_node``) and use a context dictionary (``context.eval_context``) from the context provided in their first parameter * HTML tag soup parser based on BeautifulSoup in ``lxml.html.ElementSoup`` * New module ``lxml.doctestcompare`` by Ian Bicking for writing simplified doctests based on XML/HTML output. Use by importing ``lxml.usedoctest`` or ``lxml.html.usedoctest`` from within a doctest. * New module ``lxml.cssselect`` by Ian Bicking for selecting Elements with CSS selectors. * New package ``lxml.html`` written by Ian Bicking for advanced HTML treatment. * Namespace class setup is now local to the ``ElementNamespaceClassLookup`` instance and no longer global. * Schematron validation (incomplete in libxml2) * Additional ``stringify`` argument to ``objectify.PyType()`` takes a conversion function to strings to support setting text values from arbitrary types. * Entity support through an ``Entity`` factory and element classes. XML parsers now have a ``resolve_entities`` keyword argument that can be set to False to keep entities in the document. * ``column`` field on error log entries to accompany the ``line`` field * Error specific messages in XPath parsing and evaluation NOTE: for evaluation errors, you will now get an XPathEvalError instead of an XPathSyntaxError. To catch both, you can except on ``XPathError`` * The regular expression functions in XPath now support passing a node-set instead of a string * Extended type annotation in objectify: new ``xsiannotate()`` function * EXSLT RegExp support in standard XPath (not only XSLT) Bugs fixed ---------- * lxml.etree did not check tag/attribute names * The XML parser did not report undefined entities as error * The text in exceptions raised by XML parsers, validators and XPath evaluators now reports the first error that occurred instead of the last * Passing '' as XPath namespace prefix did not raise an error * Thread safety in XPath evaluators Other changes ------------- * objectify.PyType for None is now called "NoneType" * ``el.getiterator()`` renamed to ``el.iter()``, following ElementTree 1.3 - original name is still available as alias * In the public C-API, ``findOrBuildNodeNs()`` was replaced by the more generic ``findOrBuildNodeNsPrefix`` * Major refactoring in XPath/XSLT extension function code * Network access in parsers disabled by default

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[lxml-dev] Use cssselect.py in Pyxer
by Dirk Holtwick 05 Oct '08

05 Oct '08

Hi, I wrote (yet another) templating language for Python based on Genshi, since Genshi itself does not yet work on Google App Engine (GAE). Since Genshi supports XPath I was thinking about using your cssselect.py module together with it. First tests showed that this seems to work fine. Now I would like to ship a little bit modified version of cssselect.py with this new templating language called "Pyxer" http://code.google.com/p/pyxer/ so the users do not have to install the whole lxml package (which does not work with GAE anyways I suppose). Since Python "lxml" is under the BSD license and Pyxer under MIT license I think this should not be such a big problem as long as I add your copyright notices to the file. Am I right? Thanks for your excellent work Dirk

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Re: [lxml-dev] questions about lxml xsd:include and xsd:import behavior
by Stefan Behnel 29 Aug '08

29 Aug '08

Hi, the best place to ask these questions is the lixbml2 mailing list. Stefan Santoro, Peter wrote: > After reading > http://kontrawize.blogs.com/kontrawize/2007/10/the-trouble-wit.html, I > have a couple of questions about how lxml and libxml2 handle imports and > includes. I can always run some tests to figure this out for myself, > but it would be nice if someone who already knows the official/correct > answers could share them. > > > > 1) The XML Schema standard appears to leave it up to the parser to > determine how to resolve importing multiple schemas from the same > namespace. Apparently, some parsers only import the first schema from a > given namespace, which could lead to missing definition errors. What is > the behavior of lxml/libxml2 here? > > > > 2) It appears that some xml parsers incorrectly treat multiple relative > includes of the same file as being different. This behavior would cause > the same file to be included more than once, causing redefinition > errors. What is the behavior of lxml/libxml2 here? > > > > Thank you, > > > > Peter > > _______________________________________________ > lxml-dev mailing list > lxml-dev(a)codespeak.net > http://codespeak.net/mailman/listinfo/lxml-dev >

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Re: [lxml-dev] very long files with many XML entity refs
by Stefan Behnel 29 Aug '08

29 Aug '08

Moshe Cohen wrote: > You mentioned there that it was also slow for you using xmllint. For me, > xmllint'ing it works very fast. Did you use any special options with > xmllint? Yes, for a fair comparison, I used similar options as for lxml, i.e. xmllint --noent --encode us-ascii Stefan

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[lxml-dev] very long files with many XML entity refs
by Moshe Cohen 29 Aug '08

29 Aug '08

I have a sample XML file which contains <text> .... </text> with 8,000,000 (eight million) repetitions of '&#135'. A test program for loading it and then writing it is: import sys #import cElementTree as ET from lxml import etree as ET f=open(sys.argv[1]) et = ET.ElementTree(file = f) et.write('ooo') When it is run with cElementTree , it completes successfully in about 1 minute. When it is run with lxml, it does not complete, even after 12 hours!!! and the process is constantly at 100% CPU. Further testing showed it reaches the 'write' statement quite fast and is stuck in there. Is this a bug or is lxml just dead slow relative to cElementTree , for this action? Notes: 1) Nothing special about '', it is just a simple sample with the same character repeating. The original problem showed up with a long file of various entity refs (some encoding of binary data). 2) Testing with shorter files (thousands of characters), seemed to have similar speed for cElementTree and lxml. TIA Moshe

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lxml - The Python XML Toolkit August 2008