OpenCV not working properly with python on Linux with anaconda. Getting error that cv2.imshow() is not implemented

Question

This is the exact error that I am getting. My OS is Ubuntu 16.10.

OpenCV Error: Unspecified error (The function is not implemented. Rebuild the library with

Answer 1

For my system (Ubuntu 18.04) the following was working.
First:

sudo apt-get update -y

sudo apt-get install -y libgtk2.0-dev

conda create -n py35 python=3.5

conda activate py35

Then configure the environment

pip install Cython

pip install scikit-build

conda install -c anaconda cmake

pip install dlib

pip install face_recognition

pip install imutils

And finally:

pip install opencv-contrib-python