Mailman 3 February 2011 - lxml - The Python XML Toolkit

Re: [lxml] Adding top-level comments to an ElementTree object
by Graff, Marc 01 Mar '11

01 Mar '11

Attached is a method I use to insert external xml into an existing tree Then I print out the modified tree after all mods are complete. From: lxml-bounces(a)lxml.de [mailto:lxml-bounces@lxml.de] On Behalf Of Tyler Erickson Sent: Monday, February 28, 2011 3:14 PM To: lxml(a)lxml.de Subject: [lxml] Adding top-level comments to an ElementTree object How do you add top-level comments to an ElementTree object [1]? from lxml import etree from lxml.builder import E # construct an Element class using the E-factory element = ( E.root( E.a('eggs'), ) ) # wrap with an ElementTree element_tree = etree.ElementTree(element) It appears that you can do this by parsing an XML document that contains a top-level comment (shown below), but I am unsure of how to add a top-level comment to an existing ElementTree object. from StringIO import StringIO tree = etree.parse(StringIO('''\ <?xml version="1.0"?>  <root> <a>eggs</a> </root> ''')) print etree.tostring(tree) - Tyler [1] http://lxml.de/tutorial.html#the-elementtree-class

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Adding top-level comments to an ElementTree object
by Tyler Erickson 28 Feb '11

28 Feb '11

How do you add top-level comments to an ElementTree object [1]? from lxml import etree from lxml.builder import E # construct an Element class using the E-factory element = ( E.root( E.a('eggs'), ) ) # wrap with an ElementTree element_tree = etree.ElementTree(element) It appears that you can do this by parsing an XML document that contains a top-level comment (shown below), but I am unsure of how to add a top-level comment to an existing ElementTree object. from StringIO import StringIO tree = etree.parse(StringIO('''\ <?xml version="1.0"?>  <root> <a>eggs</a> </root> ''')) print etree.tostring(tree) - Tyler [1] http://lxml.de/tutorial.html#the-elementtree-class

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Re: [lxml] lxml Digest, Vol 1, Issue 10
by Charles Norton 27 Feb '11

27 Feb '11

It's going to be a medium sized XML file. Currently, I'm using iterparse and a suggestion for pulling the name space off from an answer I received earlier. Charles M Norton Database Programmer/Systems Integrator ----- Original Message ---- From: "lxml-request(a)lxml.de" <lxml-request(a)lxml.de> To: lxml(a)lxml.de Sent: Sat, February 26, 2011 1:00:16 PM Subject: lxml Digest, Vol 1, Issue 10 Send lxml mailing list submissions to lxml(a)lxml.de To subscribe or unsubscribe via the World Wide Web, visit http://mailman-mail5.webfaction.com/listinfo/lxml or, via email, send a message with subject or body 'help' to lxml-request(a)lxml.de You can reach the person managing the list at lxml-owner(a)lxml.de When replying, please edit your Subject line so it is more specific than "Re: Contents of lxml digest..." Today's Topics: 1. Re: Clipping namespace from iterparse (Stefan Behnel) 2. Re: Problem building lxml under Windows - error: Unable to find vcvarsall.bat (Piotr Dobrogost) ---------------------------------------------------------------------- Message: 1 Date: Fri, 25 Feb 2011 17:09:21 +0100 From: Stefan Behnel <stefan_ml(a)behnel.de> Subject: Re: [lxml] Clipping namespace from iterparse To: lxml(a)lxml.de Message-ID: <4D67D431.1030203(a)behnel.de> Content-Type: text/plain; charset=UTF-8; format=flowed Brad Clements, 24.02.2011 22:11: > Is the file so big you have to use iterparse instead of something like > xpath or find? Which are not contradictory at all, BTW. In fact, it's best practice to use them together. > On 02/24/2011 03:18 PM, Charles Norton wrote: >> Thursday February 24, 2011 >> >> I am successfully parsing an XML file using etree.iterparse/ >> >> xml_name_space = '{http://www.acme.com/eeXmlExport/1.0}' >> context = etree.iterparse(fnam) >> >> for action, elem in context: >> search_tag = elem.tag[len(xml_name_space):len(elem.tag)] Note that you do not need to pass the tag length, just use elem.tag[len(xml_name_space):] Personally, I'd just use the fully qualified tag names, i.e. VALUE_TAG = '{http://www.acme.com/eeXmlExport/1.0}value' ... for _,elem in etree.iterparse(file_path): if elem.tag == VALUE_TAG: ... Stefan ------------------------------ Message: 2 Date: Fri, 25 Feb 2011 21:00:30 +0000 (UTC) From: Piotr Dobrogost <pd(a)gmane.2011.dobrogost.pl> Subject: Re: [lxml] Problem building lxml under Windows - error: Unable to find vcvarsall.bat To: lxml(a)lxml.de Message-ID: <loom.20110225T215640-513(a)post.gmane.org> Content-Type: text/plain; charset=us-ascii Stefan Behnel <stefan_ml <at> behnel.de> writes: > Because lxml has nothing to do with VC. The places to look are a) distutils Right. Thanks for help which helped me to write my answer to SO's question titled "Building lxml for Python 2.7 on Windows" (http://stackoverflow.com/questions/3047542/#5122521). ------------------------------ _______________________________________________ Mailing list for the lxml Python XML toolkit - http://lxml.de/ lxml(a)lxml.de http://mailman-mail5.webfaction.com/listinfo/lxml End of lxml Digest, Vol 1, Issue 10 ***********************************

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Problem building lxml under Windows - error: Unable to find vcvarsall.bat
by Piotr Dobrogost 26 Feb '11

26 Feb '11

Hi! I'm trying to build lxml under Windows (Vista 64bit with VS 2010 Express). I'm following instructions on http://lxml.de/build.html#static-linking-on-windows but I get the following error: (lxml-py2.6-32bit) Z:\lxml\lxml-2.3>python setup-static.py bdist_wininst --static Building lxml version 2.3. Building without Cython. ERROR: 'xslt-config' is not recognized as an internal or external command, operable program or batch file. ** make sure the development packages of libxml2 and libxslt are installed ** Using build configuration of libxslt Building against libxml2/libxslt in one of the following directories: c:\program files (x86)\lib\libxml2\lib c:\program files (x86)\lib\libxslt\lib c:\program files (x86)\lib\zlib\lib c:\program files (x86)\lib\iconv\lib running bdist_wininst running build running build_py running build_ext building 'lxml.etree' extension error: Unable to find vcvarsall.bat According to http://article.gmane.org/gmane.comp.python.lxml.devel/5462 'xslt-config' is not mandatory so let's ignore this error. Regarding the second error - error: Unable to find vcvarsall.bat - I have VC folder in my PATH and where vcvarsall.bat returns C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\vcvarsall.bat so vcvarsall.bat should be found. Any ideas? PS. Yes, I know there are binary builds available for Windows. I'd like to be able to build lxml myself, however.

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Schema validation oddity
by Andrew McHarg 25 Feb '11

25 Feb '11

I have run into a strange problem with validating a dom tree made directly by lxml not validating. However when I print it out and parse it back in it does validate! :| I am setting the schema using the default namespace with the following nsmap: schema_url = 'http://bbqs.infra.washington.edu/bqs/schema/Quota.xsd' nsmap = {None: schema_url} I imagine lxml just needs to update whatever wrapped libxml2 class that is actually doing the work with the right schema when nsmap is set? I have not checked the lxml code to see what it is doing. Andrew

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Clipping namespace from iterparse
by Charles Norton 25 Feb '11

25 Feb '11

Thursday February 24, 2011 I am successfully parsing an XML file using etree.iterparse/ xml_name_space = '{http://www.acme.com/eeXmlExport/1.0}' context = etree.iterparse(fnam) for action, elem in context: search_tag = elem.tag[len(xml_name_space):len(elem.tag)] if 'channelID' == search_tag: si_read.append(elem.text) elif 'value' == search_tag: if not elem.text: continue else: si_read.append(elem.text) First, I am wondering if there is a way to walk the XML file and read the the values from the -- for example <value>5</value> tags without having splice away the name space value. Using the following code in the python interpreter, I can find the namespace. parser = etree.XMLParser(ns_clean=True) tree = etree.parse('test.xml', parser) root = tree.getroot() Entering root prints: <Element {http://www.acme.com/eeXmlExport/1.0}intervalDataExport at 0xb71f59dc> Second, I can obtain root programmatically. Is there a way programmatically to extract what is in the braces? Thanks. cmn Charles M Norton Database Programmer/Systems Integrator

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Question on subtree parsing
by Lars Nordin 19 Feb '11

19 Feb '11

I'm not an XML / lxml expert and I have a XML that I am trying to pull info from, it looks like this: <Assets> <Asset> ... </Asset> <Asset> ... </Asset> </Assets> I run an xpath query to get the first (only) Asset element asset_tree = result_tree.xpath("/Assets/Asset")[0] # I've tried create a new etree so that the root element would be set at /Asset defect_tree = lxml.etree.ElementTree(element=asset_tree) When I run the xpath query, I am getting this error: oid_e = defect_tree.xpath('/Asset') File "etree.pyx", line 1398, in etree._ElementTree.xpath File "xpath.pxi", line 75, in etree._XPathEvaluatorBase.evaluate File "xpath.pxi", line 211, in etree.XPathDocumentEvaluator.__call__ File "xpath.pxi", line 108, in etree._XPathEvaluatorBase._handle_result File "extensions.pxi", line 284, in etree._unwrapXPathObject File "extensions.pxi", line 320, in etree._createNodeSetResult File "etree.pyx", line 1122, in etree._elementFactory File "classlookup.pxi", line 209, in etree._parser_class_lookup File "classlookup.pxi", line 73, in etree.FallbackElementClassLookup._callFallback File "classlookup.pxi", line 142, in etree._lookupDefaultElementClass AssertionError: Unknown node type: 0 This is the version of lxml that I am using: >>> print lxml.etree.__version__ 1.3.6 Am I doing something wrong or am I hitting a known bug? Is there a work around for this I do I need to upgrade lxml?

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unicode in objectify on macosx
by Henrik Genssen 18 Feb '11

18 Feb '11

Hi, I am trying to use lxml in combination with django on macosx 10.5 installed using port (py25-lxml @2.2.2_0) When I objectify an XML document, all string nodes (object properties) are str not unicode. The reason seams to be my registeredType list: [PyType(int, IntElement), PyType(float, FloatElement), PyType(bool, BoolElement), PyType(none, NoneElement), PyType(long, IntElement), PyType(str, StringElement), PyType(NoneType, NoneElement)] I did not find a sample to replace the PyType(str, StringElement) with something unicode - usable for Django. Is this the wrong way or is there another trick? regards Hinnack Henrik Genssen hg(a)miadi.net Tel. +49 (0)451/6195650 Fax. +49 (0)451/6195655 miadi GmbH Geschäftsführer: Henrik Genssen Sitz der Gesellschaft: Hüxstraße 1 - 9, 23552 Lübeck Amtsgericht Lübeck HRB 10223, USt-IdNr DE Lieferungen und Leistungen erfolgen ausschließlich auf Grundlage unserer allgemeinen Geschäftsbedingungen

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Question About XML Dump
by Charles Norton 18 Feb '11

18 Feb '11

Thursday February 17, 2011 The XML file I'm going to be parsing has the XHTML name space www.w3... and the NSMAP for the vendor who is supplying us with the XML. xmlns="http://www.skippy_test.com/eeXmlExport/1.0" Each of my tags starts with this name space; the name space is bracketed by braces. I could split of the first occurrence of this name space, save it in a variable, and pre-pend that to element tags I'm searching for. Is there a better way to do this, so the name space is filtered away? I am searching for the tags and values like this: from lxml import etree def parseHourlyReadsXML(fnam): context = etree.iterparse(fnam) all_reads = [] si_read = [] last_endpoint = 0 this_endpoint = 0 for action, elem in context: if elem.text: print(elem.tag, ' ', elem.text) if 'ID' == elem.tag: . . . Any suggestions? Thank you. Charles M Norton Database Programmer/Systems Integrator

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lxml for windows 64 bit & Python 3.1
by Grey 4500 17 Feb '11

17 Feb '11

Hello, Is there a version of lxml available for Python 3.1 running on Windows 64 bit? Will there be one available soon? On the PyPI page, there are several versions of lxml 2.2.8 available but none for this combination. I have tried building from the source but got this error: "error: Unable to find vcvarsall.bat" Thanks

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