ImportError: libSM.so.6: cannot open shared object file: No such file or directory

When trying to import OpenCV, using import cv2 I get the following error:

    /usr/local/lib/python2.7/dist-packages/cv2/__init__.py in <module>()
          7 
          8 # make IDE's (PyCharm) autocompletion happy
    ----> 9 from .cv2 import *
         10 
         11 # wildcard import above does not import "private" variables like __version__

    ImportError: libSM.so.6: cannot open shared object file: No such file or directory

Not sure how to fix this - trying to play around with Google's new Colaboratory tool. Notebook is here: https://drive.google.com/file/d/0B7-sJqBiyjCcRmFkMzl6cy1iN0k/view?usp=sharing

This fixed the problem by having it as the first two lines of the script:

    !pip install opencv-python
    !apt update && apt install -y libsm6 libxext6

From: stackoverflow.com/q/47113029