A while ago app_python3 module was added to Kamailio’s GIT master branch (to be released as stable version 5.2.0 in several months), thanks to the development efforts of Anthony Alba.
Although it started from the old app_python, besides being implemented to work with Python3, the new modules added a lot of improvements, leveraging the Python3 architecture for better performances, as well as including the support for Python script reload at runtime via an RPC command (so no need to restart Kamailio — the feature was ported to app_python meanwhile). The readme of the module is available at:
Happy SIP routing in Python3! You can learn more about the Kemi scripting languages at Kamailio World Conference 2018 — an workshop is dedicated to this topic!
Thanks for flying Kamailio!