How to use SWIG to Wrap C++ for Python

Reference: https://blog.csdn.net/u014525760/article/details/80676065

After compiling with: 

swig -python -c++ example.i && python setup.py build_ext --inplace

three more files: example.py, _example.so, example_wrap.cxx will be generated. With these files in directory, you can now import them into python for future use. Among these files, .py and .so files are necessary for use.