xml:id attribute support

[Archard Lias]

Hi,

Is there any way to specify an xml:id="someID" attribute in an lxml etree.Element. As far as I tried I got an exception from:
lxml.etree._attributeValidOrRaise (src/lxml/lxml.etree.c:29439)

when doing either of the two following lines...
e = etree.Element('asd', **{'xml:id': 'asd'}) # throws
e['xml:id'] = 'asd' # for e being a etree.Element. Throws too.

The stacktrace in that case becomes:
/usr/lib/python3/dist-packages/lxml/etree.cpython-34m-x86_64-linux-gnu.so in lxml.etree.Element (src/lxml/lxml.etree.c:68803)()
/usr/lib/python3/dist-packages/lxml/etree.cpython-34m-x86_64-linux-gnu.so in lxml.etree._makeElement (src/lxml/lxml.etree.c:15242)()
/usr/lib/python3/dist-packages/lxml/etree.cpython-34m-x86_64-linux-gnu.so in lxml.etree._makeElement (src/lxml/lxml.etree.c:15125)()
/usr/lib/python3/dist-packages/lxml/etree.cpython-34m-x86_64-linux-gnu.so in lxml.etree._initNodeAttributes (src/lxml/lxml.etree.c:16733)()
/usr/lib/python3/dist-packages/lxml/etree.cpython-34m-x86_64-linux-gnu.so in lxml.etree._addAttributeToNode (src/lxml/lxml.etree.c:17198)()
/usr/lib/python3/dist-packages/lxml/etree.cpython-34m-x86_64-linux-gnu.so in lxml.etree._attributeValidOrRaise (src/lxml/lxml.etree.c:29439)()

Do I need to specify a XML Standard namespace describing the attribute in order to legalize it for lxml? Or is it unintended behavior?

#####
Python : sys.version_info(major=3, minor=4, micro=2, releaselevel='final', serial=0)
lxml.etree : (3, 4, 0, 0)
libxml used : (2, 9, 1)
libxml compiled : (2, 9, 1)
libxslt used : (1, 1, 28)
libxslt compiled : (1, 1, 28)
#####

Best regards,
~Arlias

[Archard Lias (archardlias)]

Found the proper way to do it, by specifying {http://www.w3.org/XML/1998/namespace}id as the namespace with the <id> as the value. Probably not the best way to deal with it (not really intended for this I suppose) but works for me.

[scoder (scoder)]

Yes, this is the correct way to do it.