Mailman 3 April 2009 - lxml - The Python XML Toolkit

[lxml-dev] How to set an attribute with a xml-namepace
by Grimm, Markus April 28, 2009

April 28, 2009

Hi all, I want to set a new element with an attribute using the xml-namespace, f.e. >> xml = "<root xml:space=\"preserve\"/>" >> root = etree.fromstring(xml) >> print etree.tostring(root) <root xml:space="preserve"/> everything fine, and now... >> root = etree.Element("root", space="preserve") >> print etree.tostring(root) <root space="preserve"/> How can I bind the space-attribute to the xml-namespace, so I can output the same result as above ? Thanks, Markus

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[lxml-dev] eetree.fromsring() returns Element, expected ElementTree
by David Gardner April 28, 2009

April 28, 2009

Ran into something that maybe a bug, or at least isn't clear from the documentation [http://codespeak.net/lxml/api/lxml.etree-module.html#fromstring] because it doesn't mention a return type for etree.fromstring(). I had expected it to behave similar to etree.parse(). Currently I have a work-around of: tree = etree.ElementTree(etree.fromstring(xml_data)) See below for simple test, and output. ------- #!/usr/bin/python import sys,StringIO from lxml import etree print "lxml.etree: ", etree.LXML_VERSION print "libxml used: ", etree.LIBXML_VERSION print "libxml compiled: ", etree.LIBXML_COMPILED_VERSION print "libxslt used: ", etree.LIBXSLT_VERSION print "libxslt compiled: ", etree.LIBXSLT_COMPILED_VERSION some_xml_data = "<root>data</root>" tree1=etree.fromstring(some_xml_data) tree2=etree.parse(StringIO.StringIO(some_xml_data)) print type(tree1) print type(tree2) -------------- lxml.etree: (2, 1, 5, 0) libxml used: (2, 7, 3) libxml compiled: (2, 6, 32) libxslt used: (1, 1, 24) libxslt compiled: (1, 1, 24) <type 'lxml.etree._Element'> <type 'lxml.etree._ElementTree'> 'lxml.etree._Element' object has no attribute 'write' -- David Gardner Pipeline Tools Programmer, "Sid the Science Kid" Jim Henson Creature Shop dgardner(a)creatureshop.com

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[lxml-dev] Problem with XMLSchema and attribute_defaults
by Frank Millman April 27, 2009

April 27, 2009

Hi all I need to validate an xml document with a schema, and at the same time populate it with any default attributes. This works correctly with minixsv, but it is rather slow, so I am trying lxml. It validates correctly, but I cannot get it to load the default attributes. This is what I am doing - schema = etree.XMLSchema(file='bpmnxpdl_31.xsd') parser = etree.XMLParser(schema=schema, attribute_defaults=True) root = etree.parse('order.xml', parser) Any assistance will be appreciated. Thanks Frank Millman

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[lxml-dev] Forms, Cookies, Headers, and Time
by Akafubu Kibombo April 23, 2009

April 23, 2009

I am trying to write a script which fetches a url, logs into the site, then fetches particular items from the page, and goes to the next page, fetching the same type of files on the new page until there are no new pages to fetch from. So I need form and cooke handling, as well as manipulating the headers. What do I need to use? I found this thread, but I don't understand it: http://codespeak.net/pipermail/lxml-dev/2008-December/004272.html. Also, I don't want to wipe out the server with so many requests, is there a "wait 2 - 3 seconds before fetching the next element" type function?.. Thank you so, so much. -A.F.

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Re: [lxml-dev] lxml 2.2 released
by Stefan Behnel April 17, 2009

April 17, 2009

jasonrbriggs(a)gmail.com wrote: > Hope you don't mind a quick question -- is "from the source > distribution" the only way to install on Python 3? There are currently no binary packages (that I know of) for Py3.0 or 3.1, so, yes, you have to build it yourself. Stefan

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[lxml-dev] Porting lxml to QNX 6.4.0 issue
by Nelson Powell April 14, 2009

April 14, 2009

I've attempted to port lxml to a QNX 6.4.0 PC (x86) and have already built and installed the libxslt, libxml2, and libgcrypt libraries wihtout any compile/link issues. The libraries were installed at /usr/local/lib which is part of my LD_LIBRARY_PATH. I'm using: libxslt 1.1.22 libxml2 2.7.2 libgcrypt 11.5.2 However, after building lxml, importing lxml produces the following messages in python: bash-3.2# python Python 2.5.2 (r252:60911, Oct 8 2008, 21:15:13) [GCC 4.2.4] on qnx6 Type "help", "copyright", "credits" or "license" for more information. >>> import lxml.etree as ET unknown symbol: gcry_cipher_open unknown symbol: gcry_cipher_ctl unknown symbol: gcry_md_hash_buffer unknown symbol: gcry_cipher_close unknown symbol: gcry_cipher_encrypt unknown symbol: gcry_check_version unknown symbol: gcry_cipher_decrypt unknown symbol: gcry_strerror Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: Unresolved symbols >>> Is there a way around this libgcrypt stuff? Anyone seen this before?

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[lxml-dev] Unicode oddness
by Adam April 8, 2009

April 8, 2009

The following seems wrong to me: I have a utf-8 encoded string with html containing the word 'Français': >>> html = '<html><head><title>Fran\xc3\xa7ais</title></head></html>' I feed it to lxml.html: >>> root = lxml.html.fromstring(html) When I get the text from lxml, it is a unicode string, but it has not been decoded!: >>> root.text_content() u'Fran\xc3\xa7ais' The expected output would be decoded unicode, i.e. the result of: >>> 'Fran\xc3\xa7ais'.decode('utf-8') u'Fran\xe7ais' Or just get back the encoded utf-8 string 'Fran\xc3\xa7ais' Either of these results would make sense and work for me. But the result is an odd confusion of the two. Is this an lxml problem, or have I misunderstood something? Thanks, Adam

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[lxml-dev] Low ASCII values as text
by F Wolff April 8, 2009

April 8, 2009

Hallo list I encountered a small issue from a user's error report, and a way to duplicate the issue is from this example code: from lxml import etree l = etree.Element('cow') l.text = unicode('\xd0\x94\x1bi\x1b\x1b\x1b?', "utf-8") etree.fromstring(etree.tostring(l)) With lxml 2.1 I get: XMLSyntaxError: PCDATA invalid Char value 27, line 1, column 13 It seems that etree.tostring() can generate XML that etree.fromstring() can't handle. But with a newer version (I think a beta of 2.2), I get "All strings must be XML compatible : Unicode or ASCII, no NULL bytes" on the assignment statement (l.text = ...). So in either case my question is if lxml's handling of these low values in ASCII is correct, since it doesn't seem possible to actually represent them at all, but I guess I am missing something important. As far as I know the XML 1.0 specification demands indicating these with numeric entities. Keep well Friedel -- Recently on my blog: http://translate.org.za/blogs/friedel/en/content/monolingual-translation-fo…

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[lxml-dev] XMLSchemaParseError if XML schema namespace uri is not "http://www.w3.org/2001/XMLSchema"
by Kev Dwyer April 6, 2009

April 6, 2009

Hello, This is a re-post of my earlier posting, at Stefan's request, without the corporate boilerplate that I inadvertently sent last time. Sorry about that. Bug 354574 logged at Stefan's request. I have encountered a problem with schema object creation with lxml; the problem relates to namespace used for the root element of the schema. <snip> >>> import lxml.etree >>> et = lxml.etree.ElementTree(file=open('c:\\temp\\MySchema', 'r')) >>> et <lxml.etree._ElementTree object at 0x011B8AF8> >>> xsd = lxml.etree.XMLSchema(et) Traceback (most recent call last): File "<pyshell#4>", line 1, in <module> xsd = lxml.etree.XMLSchema(et) File "xmlschema.pxi", line 50, in lxml.etree.XMLSchema.__init__ (src/lxml/lxml.etree.c:120919) XMLSchemaParseError: Document is not XML Schema </snip> Looking in subversion (http://codespeak.net/svn/lxml/trunk/src/lxml/xmlschema.pxi), in the XMLSchema class I see: <snip> # work around for libxml2 bug if document is not XML schema at all #if _LIBXML_VERSION_INT < 20624: c_node = root_node._c_node c_href = _getNs(c_node) if c_href is NULL or \ cstd.strcmp(c_href, 'http://www.w3.org/2001/XMLSchema') != 0: raise XMLSchemaParseError, u"Document is not XML Schema" </snip> The schemas that I am using use this root element: <xsd:schema xmlns:xsd="http://www.w3.org/2000/10/XMLSchema"> If I change them to <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"> they validate. Can you explain why the earlier namespace definition is unacceptable? Is there a workaround? The schemas are not built by my application, so changing them might be an issue. Cheers, Kevin

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[lxml-dev] setting xslt output encoding with lxml
by chris hoke April 4, 2009

April 4, 2009

hi, (hope this is the right list for my question) To set the XSL output encoding I normally use <xsl:output encoding="..."/> in the stylesheet. At least in the Java based XSLT processors it is possible to set some attributes of xsl:output from the "outside" meaning when initializing or starting the transformation. So it is possible for example to overwrite any encoding specified in <xsl:output... with a different encoding. Is there any way to do this with LXML? The docs only have an example to set an XSLT parameter but not an XSLT processing configuration like the output encoding. BTW, the example on http://codespeak.net/lxml/xpathxslt.html#xslt >>> xslt_tree = etree.XML('''\ ... <xsl:stylesheet version="1.0" ... xmlns:xsl="http://www.w3.org/1999/XSL/Transform"<http://www.w3.org/1999/XSL/Transform>> ... <xsl:template match="/"> ... <foo><xsl:value-of select="$a" /></foo> ... </xsl:template> ... </xsl:stylesheet>''') >>> transform = etree.XSLT(xslt_tree) >>> f = StringIO('<a><b>Text</b></a>') >>> doc = etree.parse(f) seems to miss an <xsl:param name="a"/> parameter. I have not checked if it works without it but I guess it would be good style to declare any incoming parameters if not for setting a default value, would it not? thanks for any hints, Christof

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