This is a common trope that does not really match reality. Pytorch readme quote pytorch is not a Python binding into a monolithic C++ framework. It is built

This is a common trope that does not really match reality. Pytorch readme quote pytorch is not a Python binding into a monolithic C++ framework. It is built to be deeply integrated into Python. could be applied to many key libraries of this ecosystem. For sure, a lot of those libraries rely on tons of compiled code in C/C++/Fortran, but the python code is not mere wrapping on top of those libs. And most of the compiled code inside those repos has a lot of internal logic as well. Some examples (using cloc on git main branch, as tokei does not understand cython): * sklearn: 150 kloc python, ~10kloc cython, not much of other languages * NumPy: 200kloc python, 350kloc for C/C++ * scipy: 800 kloc C, 200 kloc python (the 800kloc surprised me and it looks like a lot of it is C generated code from cython)