Install openCV3 with Python3 on OSX

opencv3_python3.sh

#!/bin/sh

## need to make sure current python version is 3.6.1 also

pip install numpy

cmake -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=/usr/local \
    -D OPENCV_EXTRA_MODULES_PATH=~/devops/opencv_contrib/modules \
    -D PYTHON3_LIBRARY=/usr/local/opt/python3/Frameworks/Python.framework/Versions/3.6/lib/python3.6/config-3.6m-darwin/libpython3.6.dylib \
    -D PYTHON3_INCLUDE_DIR=/Users/shaw.innes/.virtualenvs/opencv/include/python3.6m \
    -D PYTHON3_EXECUTABLE=$VIRTUAL_ENV/bin/python \
    -D BUILD_opencv_python2=OFF \
    -D BUILD_opencv_python3=ON \
    -D INSTALL_PYTHON_EXAMPLES=ON \
    -D INSTALL_C_EXAMPLES=OFF \
    -D WITH_OPENCL=ON \
    -D BUILD_EXAMPLES=ON ..
    
make -j4

sudo make install

mv /usr/local/lib/python3.6/site-packages/cv2.cpython-36m-darwin.so /usr/local/lib/python3.6/site-packages/cv2.so

PYTHON_SITE_PACKAGES=`python -c "from distutils.sysconfig import get_python_lib; print(get_python_lib())"`
ln -s /usr/local/lib/python3.6/site-packages/cv2.so "$PYTHON_SITE_PACKAGES/cv2.so"