The programming language used depends on the platform you are working on, and the only platform I'm aware of that runs python and can be used for designing digital effects is Raspberry Pi. I haven't personally done any effects work on a Pi, but I've seen it done, and I know there are resources out there.
I believe the only digital effects available through PedalPCB are written in assembly (FV-1) and C (Daisy), so nothing Python-based here. Hope this helps