The ancestral charts look good. I'm sure people will find them useful. I couldn't get the descendant chart to work. It only generated a heading.
If you get a chance to tar up what was produced specifically the files DescendantIndentedTree.html, js/indentedtree.js and json/indentedtree.json I can have a look to see what just the heading appears.
The imports need changing to get it working with 4.0, but I'll send you an updated version.
Just received, much appreciated. Should I expect this to work for python 2.7 as well ?
For python3, you will need to get rid of the unicode function. I see you are importing unicode_literals, so I'm not sure why you need it.
Just thought I had to have it, can remove all those calls if not needed.
Do you plan to put this code into the add-ons repository?
Would certainly love to add them there alas I don't have commit status etc, so would need a sponsor.