It’s bit confusing if you are having long-term experience with R but need some OpenCV Python code. What worked for me

1. download and install Python 3.8.3.
2. pip install opencv-python
3. pip install opencv-contrib-python
4. although Spyder or Jupyter is recommended for data science, I went for PyCharm
5. install Atom and follow the video instructions
6. take care, numerous non working introductions out there, stick to recent version