This exists, but one of two things happen, which still significantly slows things down. Either 1) you generate multiple python instances or 2) you push the code to a different language. Both are cumbersome and have significant effects. The latter is more common in computational libraries like numpy or pytorch, but in this respect it is more akin to python being a wrapper for C/C++/Cuda. Your performance is directly related to the percentage of time your code spends within those computation blocks otherwise you get hammered by IO operations.