OpenCV install on Python 3.6: ModuleNotFoundError
Your download must have been corrupted. It happened to me too. Simply uninstall the package and use 
sudo apt-get install python open-cv
I am getting the following error when using import cv2:
ModuleNotFoundError: No module named 'cv2'
My version of Python is 3.6 64 bit. I have downloaded the whl file to install it via pip manually, and have also installed it with pip install opencv-python however I still get ModuleNotFoundError. 
pip outputs Requirement already satisfied: opencv-python in c:\...\python36\site-packages
Help would be much appreciated.