Python gives you both upsides (the easy typical case AND the custom arbitrary C/C++ code case). Granted one needs to know C/C++ and not Java.
If whatever operation you need is not already implemented by a Python module you can just write those 100 lines of fast C++ code and then call it from Python.
As far as knowing what's going on in general you can always look at the Python source code.
If whatever operation you need is not already implemented by a Python module you can just write those 100 lines of fast C++ code and then call it from Python.
As far as knowing what's going on in general you can always look at the Python source code.