参考如下
https://www.expobrain.net/2011/01/23/swig-tutorial-for-mac-os-x/
http://www.swig.org/tutorial.html
http://note.qidong.name/2018/01/hello-swig-example/
具体步骤：
swig -python -o example_wrap.c example.i
gcc -c -arch x86_64 example_wrap.c -o example_wrap.o -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7
ld -bundle -macosx_version_min 10.13 -flat_namespace \
-undefined suppress -o _example.so *.o
My environment:
High Sierra 10.13.4
Python2.7
// Xcode 9.3
// SWIG Version 3.0.12
其中-I and -L to tell gcc where the headers and libraries are on the file system.
可以通过 $(pkg-config --cflags --libs python2) 获得
如果 pkg-config --cflags --libs python2 无法执行
输入 export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/System/Library/Frameworks/Python.framework/Versions/2.7/lib/pkgconfig
(https://github.com/sbinet/go-python/issues/28)
