Mailman 3 January 2010 - lxml - The Python XML Toolkit

[lxml-dev] conditional pretty_print
by Prashant Saxena Jan. 25, 2010

Jan. 25, 2010

Hi, In short: While printing, 1. Ignore *all* attributes(keys()) of every element. 2. Ignore *certain* attributes(keys()) of every element. 3. Ignore *certain* attributes(keys()) of element with *tag* <string>. Prashant Python 2.6.2 lxml 2.2.4 The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. http://in.yahoo.com/

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[lxml-dev] Evaluate XSLT directives inside custom XSLT extension elements
by Marat Dakota Jan. 25, 2010

Jan. 25, 2010

Hi, I have a problem I couldn't find the way to solve. Sadly if it's not possible. That's the code from XSLT extensions tutorial: <xsl:template match="*"> <my:python-extension> <some-content /> </my:python-extension> </xsl:template> Everything's working cool, but I need a bit more: <xsl:template match="*"> <my:python-extension> <something><xsl:attribute name="test"><xsl:value-of select="111" /></xsl:attribute></something> </my:python-extension> </xsl:template> Let's assume that's my execute function's signature: execute(self, context, self_node, input_node, output_parent) When it's started by XSLT processor, self_node contains <something> tag with <xsl:attribute> and <xsl:value-of> tags inside it. What should I do to ask XSLT processor to evaluate it? I need to make self_node containing <something test="111" />. And even more. What if my XSLT file looks like: <xsl:template match="*"> <my:python-extension> <something> <xsl:attribute name="test"><xsl:value-of select="111" /></xsl:attribute> <my:python-extension> <xsl:attribute name="test2"><xsl:value-of select="222" /></xsl:attribute> </my:python-extension> </something> </my:python-extension> </xsl:template> I need to have execute function called for deepest <my:python-extension> first, I need to evaluate <xsl:attribute> inside it to have <my:python-extension test2="222">... And to process the rest <my:python-extension> having the result of processed <my:python-extension test2="222"> and all XSLT instructions inside. Is there a way to do it? Or maybe there is some other way to get such possibilities? Thanks. -- Marat

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[lxml-dev] pretty_print with tail
by Prashant Saxena Jan. 24, 2010

Jan. 24, 2010

Hi, A test example prints: <emission><color><red>0.231</red>kFloat<green>0.326</green>kFloat<blue>0.921</blue>kFloat</color>kColor</emission> I am using: etree.tostring(root, method="xml", pretty_print=True) May be because every element/children has a tail text. Is it possible to format the output in this way: <emission> <color> <red>0.231</red>kFloat <green>0.326</green>kFloat <blue>0.921</blue>kFloat </color>kColor </emission> Thanks Prashant Python 2.6.2 lxml 2.2.4 wxPython 2.8.10.1 XP 32 The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. http://in.yahoo.com/

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[lxml-dev] lxml newbie objectify & subclassing
by Prashant Saxena Jan. 22, 2010

Jan. 22, 2010

Hi, This is my first post. I have used python and xml earlier but on a very small scale. This time we are developing a fairly large application where primary data storage is based on xml. I have been reading the docs on the site and lxml is looking quite promising, specially the "objectify" module. Just to start with here is the first question: from lxml import etree from lxml import objectify class Attribute(objectify.ObjectifiedDataElement): """""" def __init__(self): objectify.ObjectifiedDataElement.__init__(self) self.set("datatype", "") self.set("range", "0.,1.") def asXml(self): return etree.tostring(self, method="xml", pretty_print=True) #------------------------------------------------------------------------------- class FloatAttribute(Attribute): """""" def __init__(self, tag="float", value=0.): Attribute.__init__(self) self.tag = tag self.set("datatype", "float") etree.SubElement(self, "float").text = str(value) f = FloatAttribute() print f.asXml() The above code crashes. What's wrong here? Prashant Python 2.6.2 wxPython 2.8.10.1 lxml 2.2.4 XP 32 The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. http://in.yahoo.com/

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Re: [lxml-dev] lxml newbie objectify & subclassing
by jholg＠gmx.de Jan. 22, 2010

Jan. 22, 2010

(cc-ing the list) -------- Original-Nachricht -------- > Datum: Fri, 22 Jan 2010 16:11:38 +0530 (IST) > Von: Prashant Saxena <animator333(a)yahoo.com> > An: jholg(a)gmx.de > Betreff: Re: [lxml-dev] lxml newbie objectify & subclassing > Thanks for a quick reply. > > > Why I need sub classing is because the application needs various types of > custom data types(elements), such as vector, matrix, > color etc. A collections of these data types is a node. These attributes > are created from custom xml files at run time, stored in a node, value of an > element is changed/edited using front end gui and then node is saved to > disk(xml format). You can again load the node from disk create all the > attribute at run time. > > Considering above scenario, the simplest attribute that represents a float > element is created from <FloatAttribute> class. > > Instead of using <objectify.ObjectifiedDataElement>, If I use > <etree.ElementBase>, there are no errors and code is working fine. > > The only draw back is that I have to convert string to pydata types myself > to hook with the gui, which is not difficult at all. > > If you do have some suggestions then please let me know. > > Thanks > > Prashant > > > > > ----- Original Message ---- > From: "jholg(a)gmx.de" <jholg(a)gmx.de> > To: Prashant Saxena <animator333(a)yahoo.com>; lxml-dev(a)codespeak.net > Sent: Fri, 22 January, 2010 2:55:36 PM > Subject: Re: [lxml-dev] lxml newbie objectify & subclassing > > > > > from lxml import etree > > from lxml import objectify > > > > class Attribute(objectify.ObjectifiedDataElement): > > """""" > > def __init__(self): > > objectify.ObjectifiedDataElement.__init__(self) > > self.set("datatype", "") > > self.set("range", "0.,1.") > > > > def asXml(self): > > return etree.tostring(self, method="xml", pretty_print=True) > > > > > #------------------------------------------------------------------------------- > > > > > > class FloatAttribute(Attribute): > > """""" > > def __init__(self, tag="float", value=0.): > > Attribute.__init__(self) > > self.tag = tag > > self.set("datatype", "float") > > etree.SubElement(self, "float").text = str(value) > > > > > > f = FloatAttribute() > > print f.asXml() > > > > The above code crashes. What's wrong here? > > Please take a look at > http://codespeak.net/lxml/element_classes.html > especially: > http://codespeak.net/lxml/element_classes.html#element-initialization > > Note that Elements get instantiated through the Element()/DataElement > factory functions. > > Holger > > -- > Jetzt kostenlos herunterladen: Internet Explorer 8 und Mozilla Firefox 3.5 > - > sicherer, schneller und einfacher! http://portal.gmx.net/de/go/chbrowser > > > > The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. > http://in.yahoo.com/ -- Haiti-Nothilfe! Helfen Sie per SMS: Sende UIHAITI an die Nummer 81190. Von 5 Euro je SMS (zzgl. SMS-Gebühr) gehen 4,83 Euro an UNICEF.

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Re: [lxml-dev] lxml newbie objectify & subclassing
by Stefan Behnel Jan. 22, 2010

Jan. 22, 2010

Prashant Saxena, 22.01.2010 13:53: > The bug is reported in bug tracker. > BTW, the code below is not working because of a bug or this feature is not been implemented? It's a bug because of a feature that is implemented in lxml.etree but not in lxml.objectify, so it's a bit of both. ;) > As of now, I would prefer to use <etree.ElementBase> as it is more pythonic & easy to implement, compare to methods explained > here: > http://codespeak.net/lxml/element_classes.html#element-initialization Not sure what you mean exactly. The ElementBase class is only meant for subtyping, not for direct usage. Could you provide some background about your use case? Stefan

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[lxml-dev] lxml newbie xpath as connections
by Prashant Saxena Jan. 22, 2010

Jan. 22, 2010

Hi, This is regarding xpath and making some virtual connections in a xml file. txt=""" <node> <emission datatype="colorarray"> <color> <red>0.1</red> <green>0.2</green> <blue>0.3</blue> </color> <color> <red>0.4</red> <green>0.5</green> <blue>0.6</blue> </color> </emission> <diffuse datatype="colorarray"> <color> <red>0.1</red> <green>0.2</green> <blue>0.3</blue> </color> <color> <red>0.4</red> <green>0.5</green> <blue>0.6</blue> </color> </diffuse> <connection> <output>/node/emission/color[0]/red</output> <input>/node/diffuse/color[1]/blue</input> </connection> </node> """ o = objectify.fromstring(txt) Considering the above example, once <txt> is parsed, I could get the value of connection>output using >> print o.connection.output but it's a text. Is it possible to define connection>output in such a way, that once parsed connection>output should refer to element it is pointing by path as text. If not at the time of parsing then using xpath later, I tried: >> r = o.xpath(str(o.connection.output)) >> r.pyval I am getting an empty list. How ever if I try: >> r = o.xpath("/node/emission/color/red") >> print r r is list containing two values for each "red" of "color". How do I precisely get: /node/emission/color[0]/red Thanks Prashant Python 2.6.2 wxPython 2.8.10.1 lxml 2.2.4 XP 32 The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. http://in.yahoo.com/

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[lxml-dev] [Bug 488222] Feature request: add better schematron support to lxml
by jholg＠gmx.de Jan. 18, 2010

Jan. 18, 2010

Hi, having played around with schematron a bit more I propose some changes to the current trunk additions for iso-schematron support: The "validation criteria", i.e. if the validation result is True or False, is currently exposed on a module level: # svrl result accessors svrl_validation_errors = _etree.XPath( '//svrl:failed-assert', namespaces={'svrl': SVRL_NS}) So you can customize the criteria globally. With schematron however you can use "assert" as well as "report" tests, and also categorize the tests using "flag" and "role" attributes that will show up in the resulting svrl xml document (I do not currently understand the intended difference between the two, but that's another story). So I think it may well be possible that what's interpreted as a validation error depends very much on how one designs the schematron schema, and it may be helpful to be able to customize validation outcome per validator instance. This speaks for pulling the result accessor into the Schematron class, probably as a class attribute that can be overridden on an instance level. The same might make sense for the iso-schematron implementation xsl transformation steps. Opinions? Holger -- Preisknaller: GMX DSL Flatrate für nur 16,99 Euro/mtl.! http://portal.gmx.net/de/go/dsl02

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[lxml-dev] Namespaces on attribute values
by Mike MacCana Jan. 17, 2010

Jan. 17, 2010

Hi Stefan and others, I'm currently creating a particularly tricky element from a string, using: etree.fromstring('''<dcterms:created xmlns:xsi=" http://www.w3.org/2001/XMLSchema-instance" xmlns:dcterms=" http://purl.org/dc/terms/" xsi:type="dcterms:W3CDTF">2010-01-01T21:07:00Z</dcterms:created>''') which works fine. However I'd like to make the element manually. This bit is causing me trouble: xsi:type="dcterms:W3CDTF" is 'dcterms' a namespace on a attribute value? If so, how can I set it in LXML? I haven't seen that before, and I can't find much documentation online. I'm quite comfortable with namespaces on tags and elements. Here's what I currently have: bar = etree.Element('{http://purl.org/dc/terms/}'+'created') bar.set('{http://www.w3.org/2001/XMLSchema-instance}'+'type', 'dcterms:W3CDTF') bar.text = '2010-01-01T21:07:00Z' Alas the app that parses my XML doesn't like it - though the fromstring() is fine. Any way I can set the namespace on attribute value? Thanks very much for any help, Mike

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[lxml-dev] Problems loading lxml in MacOS 2.6 Snow Leopard...
by Martin Fisher Jan. 17, 2010

Jan. 17, 2010

Hi Guys, I think I've searched diligently but can't find a good solution: I'm seeing the following error when loading docx... ImportError: dlopen(/Library/Python/2.6/site-packages/lxml-2.2.4-py2.6-macosx-10.6-universal.egg/lxml/etree.so, 2): Symbol not found: _htmlParseChunk Referenced from: /Library/Python/2.6/site-packages/lxml-2.2.4-py2.6-macosx-10.6-universal.egg/lxml/etree.so Expected in: flat namespace in /Library/Python/2.6/site-packages/lxml-2.2.4-py2.6-macosx-10.6-universal.egg/lxml/etree.so I used easy_install to install lxml and macports to load libxml2,libxslt after cleaning/removing all versions. Any clues where to look will be appreciated. Thanks Martin Ozone Online Martin Fisher Title: CTO phone: 415-692-4182 email: martin(a)ozoneonline.com fax: 415-771-5530

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