lxml returns an empty list on DTD attributes

Question

I'm trying to get the attributes of a DTD element to get their default values but attributes() is returning always an empty list. Here is the code:

#!/usr/bin/python3 -BEOObbs
# coding=utf-8

import io, lxml.etree

xml = lxml.etree.parse(io.BytesIO(b'''<?xml
    version='1.1'
    encoding='utf-8'
?>
<!DOCTYPE root [
    <!ATTLIST test
        attr (A | B | C) 'B'
    >
    <!ELEMENT test (#PCDATA)>
    <!ELEMENT root (test)*>
]>
<root></root>'''))
element = xml.docinfo.internalDTD.elements()[0]
print(element.name)
print(element.attributes())

This is the result:

sworddragon@ubuntu:~/tmp$ ./test.py
test
[]

I'm wondering what is wrong here.

Answer 1

I have opened a ticket for this (https://bugs.launchpad.net/lxml/+bug/1266171) and they have confirmed this as a bug and even committed a fix into the master tree of the git repository so the changes will be in the final 3.3.0 release of lxml.