Python xml etree DTD from a StringIO source?

Question

I\'m adapting the following code (created via advice in this question), that took an XML file and it\'s DTD and converted them to a different format. For this problem only t

Answer 1

Here's a short but complete example, using the custom resolver technique @Steven mentioned.

from StringIO import StringIO
from lxml import etree

data = dict(
    xml_file = '''<?xml version="1.0"?>
<!DOCTYPE x SYSTEM "a.dtd">
<x><y>&eacute;zz</y></x>
''',
    dtd_file = '''<!ENTITY eacute "&#233;">
<!ELEMENT x (y)>
<!ELEMENT y (#PCDATA)>
''')

class DTDResolver(etree.Resolver):
     def resolve(self, url, id, context):
         return self.resolve_string(data['dtd_file'], context)

xmldoc = StringIO(data['xml_file'])
parser = etree.XMLParser(dtd_validation=True, load_dtd=True)
parser.resolvers.add(DTDResolver())
try:
    tree = etree.parse(xmldoc, parser)
except etree.XMLSyntaxError as e:
    # handle xml and validation errors

Answer 2

You could probably use a custom resolver. The docs actually give an example of doing this to provide a dtd.