This is Python port of https://github.com/gorhill/PHP-FineDiff, library for string diff.
import finediff
finediff.FineDiff('abcdef', 'badefo').renderDiffToHTML()'<del>a</del>b<del>c</del><ins>a</ins>def<ins>o</ins>'
pip install https://github.com/sharpden/python-finediff/tarball/master