Also, I've got a python package that's kind of my personal API [0], so I just tried to demonstrate how would similar analysis look for me using my.fbmessenger module [1]. Not as pretty as in chatistics, but just few lines of code. The hardest bit, of course, is encapsulating all the complexity of message processing in my. package.

[0] https://github.com/karlicoss/my

[1] https://beepb00p.xyz/mypkg.html#messenger_stats