title: import opencv vs import cv2
body: <p>I recently installed opencv-python-3.4.0.12 via pip install on Mac OS. When I run the Python interpreter, <code>import cv2</code> works fine whereas <code>import opencv</code> raises ModuleNotFoundError. However, when I run the Python3 Interpreter, <code>import opencv</code> works fine whereas <code>import cv2</code> raises ModuleNotFoundError. </p>
  
  <p>What is the reason behind this difference and on a related note, should I use <code>import opencv</code> or <code>import cv2</code>? Does <code>cv2</code> refer to OpenCV version 2?</p>