#Know the reason is really dumb, because the reason is that the package of CV2 is not called cv2 but called opencv-python
pip install opencv-python
#For python3:
pip3 install opencv-python
in the terminal paste this
this will surely work
pip3 install --upgrade https://storage.googleapis.com/tensorflow/mac/cpu/tensorflow-1.0.0-py3-none-any.whl