cv2cpython github code example
Example: ImportError: /usr/local/lib/python3.7/dist-packages/cv2/cv2.cpython-37m-arm-linux-gnueabihf.so: undefined symbol: __atomic_fetch_add_8
sudo pip3 install opencv-contrib-python==3.4.6.27
sudo pip3 install opencv-contrib-python==3.4.6.27