SimGuruModSquad has published a forum post on The Sims Official Forums saying that The Sims 4’s upcoming update is going to change and upgrade the current version of Python – a programming language and software which is used to help develop the game itself.
The upgrade will change the .pyo extension which is going to be replaced by .pyc. This change is going to affect ALL script mods meaning that since November they’ll completely stop functioning.
SimGuruModSquad wanted to make sure that all modders are ready and aware of this change so they can prepare and upgrade their script mods in time.
I want to give you a heads up that in an upcoming release, we will be upgrading the version of Python used by the game. We currently use Python 3.3.5 and will be moving to Python 3.7.0. Once this change is released, all compiled script mods will completely stop working. Note that in this new version of Python, the .pyo extension is replaced by .pyc, see https://www.python.org/dev/peps/pep-0488/
We know this will have impact on your script mod authoring pipelines so wanted to provide notice in advance so you can be ready for the change when it arrives. To assist, I’ve attached the Python scripts from the currently released version of the game (v1.46.18) recompiled under Python 3.7.0.
If all goes as planned, this change should arrive in November.
Note that there will not be any fundamental changes to tuning data, other than the typical types of changes we make to tuning for patches.