S7 was designed for serious computer music, and comes out of CCRMA at Stanford. While I like Python (I did it professionally for 10+ years!) generally speaking

S7 was designed for serious computer music, and comes out of CCRMA at Stanford. While I like Python (I did it professionally for 10+ years!) generally speaking in computer music embedding Python is a non-starter because of the GIL - it does not play well in apps where you have thread and performance issues, which in real time computer music, is basically a given. S7 on the other hand is very easy to use in that context, you can turn the garbage collector on and off, and have multiple instances in different threads with no issue. I really like Python, but have totally given up on it for music applications. There exist Python music libraries, but honestly, no one who really knows that field uses it in apps, though they may use it as a preprocessor for score data.