- How to install the .so files to Python library like pip?
 - How to package the python file and .so files to an executable file?
 - PyInstaller is too slow to package the files.
Thanks 
Hello! Here is a guide: Packaging binary extensions — Python Packaging User Guide
It the full packaging docs are TL;TR, then
https://setuptools.pypa.io/en/latest/userguide/ext_modules.html
or  Building Cython code — Cython 3.0.2 documentation
(and adapt for non-Cython builds)