Python xml.dom.minidom.parse() function ignores DTDs

Question

I have the following Python code:

import xml.dom.minidom
import xml.parsers.expat

try:
    domTree = ml.dom.minidom.parse(myXMLFileName)
except xml.parsers.expat.ExpatError, e:
    return e.args[0]

which I am using to parse an XML file. Although it quite happily spots simple XML errors like mismatched tags, it completely ignores the DTD specified at the top of the XML file:

<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<!DOCTYPE ServerConfig SYSTEM "ServerConfig.dtd">

so it doesn't notice when mandatory elements are missing, for example. How can I switch on DTD checking?

Answer 1

I believe you need to switch from expat to xmlproc.
See: http://code.activestate.com/recipes/220472/

Answer 2

See this question - the accepted answer is to use lxml validation.

Answer 3

I recommend lxml over xmlproc because the PyXML package (containing xmlproc) is not being developed any more; the latest Python version that PyXML can be used with is 2.4.

Answer 4

Just by way of explanation: Python xml.dom.minidom and xml.sax use the expat parser by default, which is a non-validating parser. It may read the DTD in order to do entity replacement, but it won't validate against the DTD.

gimel and Tim recommend lxml, which is a nicely pythonic binding for the libxml2 and libxslt libraries. It supports validation against a DTD. I've been using lxml, and I like it a lot.

Answer 5

Just for the record, this is what my code looks like now:

from lxml import etree

try:
    parser = etree.XMLParser(dtd_validation=True)
    domTree = etree.parse(myXMLFileName, parser=parser)
except etree.XMLSyntaxError, e:
    return e.args[0]