lxml - The Python XML Toolkit October 2008

lxml@python.org

16 participants
18 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] 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] NotImplementedError for external functions with xsl:variable's
by Dmitri Fedoruk 11 Nov '08

11 Nov '08

Greetings, We've been using lxml for almost a year now. Recently we were stuck with XSLT functionality and eventually started to use external functions, which are pretty useful in many cases. Of course, this makes the template unportable, but we deal with this. So, we register the functions in our namespace for the transformer and use them like this: <?xml version="1.0" encoding="utf-8"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fe="http://rambler.ru/fe" extension-element-prefixes="fe"> <xsl:template match="/"> query=<xsl:value-of select="fe:quote($query)"/> </xsl:tempalte> Here $query is the external parameter passed to the transformer. Works fine. But when we slightly modify the template and want to use not the external parameter, but xsl:variable, we fail: <xsl:template match="/"> <xsl:variable name="query1">asdfadsfadsf</xsl:variable> query=<xsl:value-of select="fe:quote($query1)"/> </xsl:tempalte> We have lxml 2.0.1 in production and 2.1 on the development machine. The problem occurs, but in slightly different manner, in both situations. 2.0.1 just performs nothing and returns an empty string; 2.1 raises File "xslt.pxi", line 515, in lxml.etree.XSLT.__call__ (src/lxml/lxml.etree.c:90526) File "lxml.etree.pyx", line 233, in lxml.etree._ExceptionContext._raise_if_stored (src/lxml/lxml.etree.c:4916) File "extensions.pxi", line 665, in lxml.etree._extension_function_call (src/lxml/lxml.etree.c:82995) File "extensions.pxi", line 513, in lxml.etree._unwrapXPathObject (src/lxml/lxml.etree.c:81828) NotImplementedError As far as I can understand, this situation is handled explicitly in 2.1 and there are reasons for that. So, may I ask if it is implemented sometime later? Cheers, Dmitri

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[lxml-dev] lxml Mac installation idea
by Ian Bicking 04 Nov '08

04 Nov '08

So... I hear that lxml installs better on a Mac if it's built along with libxml2/libxslt. That's not what everyone would do, so I was unclear how to enable something like that, and if setup.py would be the right place. A number of attempts to get stuff setup have been tried before external to lxml (like buildouts and now staticlxml). While it's kind of lame, I wonder if enabling this static installation via an environmental variable would be reasonable? It would be easier to apply in a number of circumstances. I imagine it would mean something like, on installation, if a variable like LXML_INSTALL_STATIC (or INSTALL_LIBXML2 or something) was set, it'd download the libxml2 and libxslt libraries, run configure/make/make install with a prefix inside the lxml source directory itself, then build lxml using that library. Another option would be simply a different tarball that contains the libxml2/libxslt source, and its setup.py would always build those. It could be versioned like 2.1static or something, which should keep it from being implicitly used by easy_install, etc. (since 2.1static is considered an earlier version than 2.1). This might be more reasonable? staticlxml is kind of weird, because installing staticlxml installs lxml, which can confuse tools. Maybe the two versions could be arranged with some svn:externals, or just as a build script of some sort (e.g., drop a marker file in the source to make it "static", and have setup.py look for that file and change the sdist/install commands appropriately). One nuisance with any attempt to fix this is that I don't think either myself nor Stefan have ready access to a Mac to test this stuff... are there any Macs we can ssh into for testing? (Obviously patches are also welcome, but this Mac thing has caused so many support problems for me that I really want to get it resolved.) -- Ian Bicking : ianb(a)colorstudy.com : http://blog.ianbicking.org

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[lxml-dev] lxml RelaxNG validation on hand-built documents
by Atilla 30 Oct '08

30 Oct '08

I've had a very curious issue that I'm trying to find the cause about. Basically - if I try to validate a document tree that was dynamically created by lxml with a relaxNG schema, the validation step passses even if there are invalid elements. If I serialize that same tree to a string and parse it once again, the newly created XML document fails the validation. Given that I expect to process fairly large trees, I'd rather not have to copy so much nformation in memory on every attempt to validate a document. Is there any reason why lxml wouldn't validate items that have been newly created and inserted into the tree, or this is a bug? How would I make sure a tree is valid, according to a schema, before I serialized and saved it ? Basically what i do is: >>>schema = etree.RelaxNG(file="schema.rng") >>>doc = etree.fromstring("<valid></valid>") >>>schema(doc) True >>>doc[0].append(etree.Element("invalid)) >>>schema(doc) True >>>schema(etree.fromstring(etree.tostring(doc))) False It's really making me think I don't get some point in the whole validation process. In hindsight - I had the same issues wiht the Perl LibXML bindings at some point in the past. Is it maybe Libxml -related ? Cheers,

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[lxml-dev] Building lxml 2.1.2 on windows
by Cserna, Zsolt (IT) 30 Oct '08

30 Oct '08

Hi all, I'm trying to build lxml 2.1.2 for python 2.5 on windows, but the linking fails with the following error: lxml.etree.obj : error LNK2019: unresolved external symbol _xsltProcessOneNode referenced in function ___pyx_pf_4lxml_5etree_13XSLTExtension_apply_templates I would like to link the libxml and the other libraries to lxml dynamically, not statically. Is it possible? It seems to me that xsltProcessOneNode is not defined in the windows version of libxslt (btw it's not defined in any .h files), however it's defined in unix .so files. I've installed all the dependencies, libxml version 2.6.31, libxslt 1.1.22, zlib 1.2, iconv 1.9, and using VC7.1 for building. Could you please advice on this? Any help/ideas would be appreciated. Thanks, Zsolt -------------------------------------------------------- NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.

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lxml - The Python XML Toolkit October 2008