Mailman 3 March 2010 - lxml - The Python XML Toolkit

[lxml-dev] Namespace redundancy in new elements
by Jennifer Rogers March 17, 2010

March 17, 2010

Hello, I'm using lxml to build Excel spreadsheets in the Office Open XML format. I've found that it is particularly picky about using specific namespace prefixes, even though prefixes aren't supposed to matter in XML so long as the URI is consistent. I've been able to get around this in most cases using namespace mappings, but I got tripped up in one particular instance. The root element of one of my xml documents looks like this: ------------------------- <workbook xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships"> ------------------------- These namespace prefixes are inherited perfectly fine by the rest of the document in any instance that uses no prefixes or that has a tag that uses a prefix. However, I'm getting stuck when I try to create a subelement that has an attribute that uses a prefix. The new element should read like this (with some context): ------------------------- <sheets> <sheet sheetId="1" name="Sheet1" r:id="rId1" /> </sheets> ------------------------- However, when I try to create this element, it turns out like this instead: ------------------------- <sheets> <sheet xmlns:r="http://schemas.openxmlformats.org/package/2006/relationships" sheetId="1" name="Sheet1" r:id="rId1" /> </sheets> ------------------------- I realize that it shouldn't matter. However, Excel is throwing a fit over my spreadsheet until I uncompress the .xlsx file, manually delete the redundant namespace binding, and recompress. Here is the (simplified) code I'm using now to create this element, where mytree is the relevant ElementTree object: ------------------------- NSMAIN = "http://schemas.openxmlformats.org/spreadsheetml/2006/main" NSRELS = "http://schemas.openxmlformats.org/package/2006/relationships" E = ElementMaker(nsmap={None: NSMAIN, 'r': NSRELS}) ... new_element = E.sheet(name='Sheet1', sheetId='1') new_element.set('{%s}id' % NSRELS, 'rId1') target_element = mytree.xpath('//ns:sheets', namespaces={'ns': NSMAIN})[0] target_element.append(new_element) ------------------------- Is there any way to define the r:id attribute without repeating the namespace binding within the element? I haven't used lxml before, and am new to Python in general, so if I'm overlooking something entirely obvious, I apologize. Thanks, Jen

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[lxml-dev] XSLT extension elements appending text to output_parent problem
by Marat Dakota March 12, 2010

March 12, 2010

Hi, I've got a problem. If I have XSLT like: ... <xsl:template match="/"> <my:ext>Test1</my:ext> <br /> <my:ext>Test2</my:ext> </xsl:template> ... And my XSLT extension element's code looks like: ... def execute(self, context, self_node, input_node, output_parent): # I just want to copy extension element's text to result output_parent.text += self_node.text ... The thing I want to get in result is: ... Test1<br />Test2 ... But I get: Test1Test2<br /> And in theory of texts and tails it's pretty ok. The problem is when the things come to processing second extension element, output_parent contains <br /> element already and I have to set it's tail to get desired result. But tail is read only. I see two possible solutions: 1) make tail of output_parent's children writable; 2) create some element class that will be turned to text during serialization to be able to do things like: ... def execute(self, context, self_node, input_node, output_parent): output_parent.append(etree.TextElement(self_node.text)) ... -- Marat

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[lxml-dev] bug in id function ?
by Sergio Monteiro Basto March 12, 2010

March 12, 2010

Hi, strxpath = 'id("tit")|id("det")' divs=etree_document.xpath(strxpath) elembody = html.Element("body") print divs[0] <Element div at 90140ec> elembody.append(divs[0]) # move the id to other tree. divs=etree_document.xpath(strxpath) # calculate again print divs[0] <Element div at 90140ec> # the element is the same, but was delete from etree_document #with strxpath = '//*[@id="titNot" or @id="detNot"]' #the things works like expect. divs=etree_document.xpath(strxpath) elembody = html.Element("body") print divs[0] <Element div at 90140ec> elembody.append(divs[0]) # move the id to other tree. divs=etree_document.xpath(strxpath) # calculate again print divs[0] # is the other element <Element div at a7cd4ac> Thanks, -- Sérgio M. B.

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[lxml-dev] Add stylesheet PI to xml doc
by James Kessler March 11, 2010

March 11, 2010

Hello, Is there a simple way to prepend an xml-stylesheet PI to an document? Thanks, James

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[lxml-dev] Comments stripping issue during html parsing
by Nicolas Delaby March 11, 2010

March 11, 2010

Hi, I'm wonder why the code above do not strip the first comment (inside style node). Is there is something particular with style nodes that i missed ? from lxml import etree from lxml.etree import HTMLParser parser = HTMLParser(remove_comments=True) html_string = '<html><body><style></style></body></html>' print etree.tostring(etree.HTML(html_string, parser=parser), pretty_print=True) <html> <body> <style></style> </body> </html> Best regards, Nicolas -- Nicolas Delaby Nexedi: Consulting and Development of Libre / Open Source Software http://www.nexedi.com/

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[lxml-dev] Request: etree.Element.set() returns self
by James Fisher March 8, 2010

March 8, 2010

Hi, Would people appreciate the convenience of the Element.set() method returning itself, allowing strung-together method calls (jQuery style)? I ask because I want to do something like this: etree.SubElement(self.head, "meta").set("http-equiv", "Content-Type").set("content", "text/html; charset=utf-8") Where I can't use http-equiv as a kwarg due to characters, and nor can I put "content" as a kwarg as I want the order of the attributes preserved. Is there a technical reason why we couldn't have this? Does set() return anything currently? (I can't find its definition.) Best James

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[lxml-dev] Converting HTML to XML
by James Johnston March 5, 2010

March 5, 2010

Thanks Manu. I've been trying to add to my meager Python knowledge and working with the lxml tutorial already. I'll look at the XSLT stuff you sent as well. I appreciate your help and guidance. Jim. -- James Johnston (615) 251-2792 james.johnston(a)lifeway.com

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[lxml-dev] Converting HTML to XML
by James Johnston March 5, 2010

March 5, 2010

I've been given an assignment to use HTML content as input to create XML. What are a few good resources? This is all pretty new to me so I apologize up front before I ask really obvious questions. I have a general and fuzzy idea about what this might entail like importing lxml.html. Conceptually, I want to read an HTML document, strip out or ignore parts of it, convert HTML tags to XML for certain references, and put the associated data into CDATA format and output an XML file. Effectively this will be used to add cross-reference comments to an existing XML document on the same basic subject. For example, the existing XML may have a section on circular saws, and the HTML document has a short article on circular saws that we want to link to in the new XML format. Thanks -- James Johnston james.johnston(a)lifeway.com

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[lxml-dev] namespaces
by Vojtěch Rylko March 3, 2010

March 3, 2010

Hi! Can I ask for a little help? I have xml: ==================== <rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:source="http://tailrank.com/ns/#post"> <channel> <item> <title>Nouveau stage : Le micashift - Les crations de Nathalie</title> <link>http://nathalie.creations.over-blog.com/article-nouveau.html</link> <guid>http://nathalie.creations.over-blog.com/article-nouveau.html</guid> <pubDate>Thu, 25 Feb 2010 21:56:24 GMT</pubDate> <dc:source>http://nathalie.creations.over-blog.com/</dc:source> <source:title>Les crations de Nathalie</source:title> </item> </channel> </rss> ==================== And code: ==================== from lxml import etree tree = etree.parse("./data.xml") print tree.xpath("dc:source")[0].text ==================== But: "lxml.etree.XPathEvalError: Undefined namespace prefix" Why? How I can use namespace defined in <rss>? I spent two days with it :( rss.attrib == 'version="2.0"' - nothink about namespaces... And in documentation I didnt found anything. Just: >langNS = etree.FunctionNamespace("http://purl.org/dc/elements/1.1/") >langNS.prefix = "dc" which is manual work... Thanks for your answers! Vojta

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Re: [lxml-dev] [Bug 488222] Feature request: add better schematron support to lxml
by jholg＠gmx.de March 3, 2010

March 3, 2010

> > 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. > > Sounds like a much better interface. Any interesting global options would > be better overridden by subtyping the validator class, so class attributes > make sense to me. Committed to trunk: https://codespeak.net/viewvc/?view=rev&revision=71090 This simply exposes the skeleton xslt steps and the validation result xpath as class attributes. I consider the iso-schematron works pretty much finished for now... Holger -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

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