Set up OpenCV for Python in MacOS X

Install/update Xcode from App Store and launch it to pass through terms agreement prompts.

Install Xcode Command Line Tools for easing later processes.

xcode-select --install

c.f. Stack Overflow thread

Install OpenCV.

$ brew install gcc
$ brew install opencv3

Now install python modules for OpenCV.

$ pip install cv2

You have to provide a shared library for it.  This is the key step. 

$ pushed /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages
$ ln -s /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/cv2.so
$ popd

Test if it works.

$ python
>>> import cv2
>>>  

It should finish without showing any error.

If this is for your virtualenv, do similarly in your venv directory.