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?

score 5 · Accepted Answer · edited May 23 '17 at 11:48

5

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

edited May 23 '17 at 11:48

Community

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1

answered Nov 18 '08 at 14:11

gimel

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Thanks. I'd hoped to avoid having to work outside the standard library, but lxml certainly does the trick. A lot easier to read, too. – Charles Anderson Nov 18 '08 at 15:50

score 3 · Answer 2 · answered Nov 18 '08 at 15:04

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.

score 2 · Answer 3 · answered Nov 18 '08 at 16:33

2

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]

answered Nov 18 '08 at 16:33

Charles Anderson

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score 1 · Answer 4 · answered Nov 18 '08 at 14:20

1

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.

answered Nov 18 '08 at 14:20

Tim Pietzcker

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score 0 · Answer 5 · answered Nov 18 '08 at 14:09

0

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

answered Nov 18 '08 at 14:09

acrosman

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

5 Answers5