Skip to main content

Compares two XML documents by diffing their text, ignoring structure, and wraps changed text in <del>/<ins> tags.

Project description

Compares the text inside two XML documents and marks up the differences with <del> and <ins> tags.

This is the result of about 7 years of trying to get this right and coded simply. I’ve used code like this in one form or another to compare bill text on <>.

The comparison is completely blind to the structure of the two XML documents. It does a word-by-word comparison on the text content only, and then it goes back into the original documents and wraps changed text in new <del> and <ins> wrapper elements.

The documents are then concatenated to form a new document and the new document is printed on standard output. Or use this as a library and call compare yourself with two lxml.etree.Element nodes (the roots of your documents).

The script is written in Python 3. The module works with any Google Diff Match Patch-compatible differencing library. You provide it a differ function which takes two strings and returns a list of (op, length) tuples, where op is “+” (insertion), “-” (deletion), or “0” (no change). If will use my extension module <> if it is available, falling back on the pure-Python <> if it is available, or else the not very useful Python built-in difflib.


Comparing these two documents:

        Here is <b>some bold</b> text.


        Here is <i>some italic</i> content that shows how <tt>xml_diff</tt> works.


                Here is <b>some <del>bold</del></b><del> text</del>.
                Here is <i>some <ins>italic</ins></i><ins> content that shows how </ins><tt><ins>xml_diff</ins></tt><ins> works</ins>.

First install the module:

pip install xml_diff

On Ubuntu, apt-get installing python3-lxml or libxml2-dev and libxslt1-dev might be necessary. When installing from source, you’ll need lxml too (but pip will get it for you automatically).

Then call the module from the command line:

python -m xml_diff  --tags del,ins doc1.xml doc2.xml > changes.xml

For really fast comparisons, get Google’s Diff Match Patch library <>, as re-written and sped-up by @leutloff <> and then turned into a Python extension module by me <>:

pip install diff_match_patch_python

The command-line tool (above) will use this library if it is available.

Use the module from Python like so:

import lxml.etree
from xml_diff import compare

dom1 = lxml.etree.parse("doc1.xml").getroot()
dom2 = lxml.etree.parse("doc2.xml").getroot()
compare(dom1, dom2)

The two DOMs are modified in-place.

If you can’t install diff_match_patch_python, you can also get the pure-Python version of from <>. (The command-line tool will fall back to this library if it is available.)

Or you can pass in your own comparison library as the third argument. (See xml_diff/’s default_differ function for how it would work.)

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

xml_diff-0.6.0.tar.gz (11.0 kB view hashes)

Uploaded source

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page