前提你已经在Mac上安装了Python3
1，安装opencv
brew up
brew install opencv
2，
homebrew安装的程序位置都在 下面。
/usr/local/Cellar/
所以我们需要找到的就是opencv的cv2*.so文件，我的文件路径为：
/usr/local/Cellar/opencv/3.3.1_1/lib/python3.6/site-packages/cv2.cpython-36m-darwin.so
3，opencv和python3环境关联
终端进入目录：/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages
执行：
ln -s /usr/local/Cellar/opencv/3.3.1_1/lib/python3.6/site-packages/cv2.cpython-36m-darwin.so cv2.so
4，测试是否成功
- >>> import cv2
- >>> cv2.__version__
