There is a python library for Wechat, but I'm having problems using it. Also, 1) getting and then 2) decrypting the Wechat database isn't easy. Because my phone is not rooted, I had to use an android emulator on my PC, transfer all my chats over there, extract the DB and all media. After installing all the fickle dependencies of the bruteforce decrypter, it took three days straight on my laptop from 2014 to decrypt, and now I can finally open it in an SQLite viewer. But that still leaves the major step of getting formatted messages out of there like in the OP. The HTML-conversion script that I used produced half-decent results, but hasn't been maintained for a while and thus chokes on certain messages so that the conversion of large chats invariably breaks down before being finished. Anyway. Maybe it is time to learn Python...