This is a small example of building a C++ library which reads and returns arrays and schemas linked against libarrow (but DOES NOT REQUIRE pyarrow), and building a python extension that uses this library to pass arrays and schemas back and forth.
This utilizes Apache Arrow's ABI-stable C interface and PyCapsule interface, which would, for example, allow your combined C++/python extension to compile and link against one version of arrow and be utilized with pyarrow which would otherwise be ABI-incompatible.