pip install pytesseract
If you don't have tesseract executable in your PATH, include the following:
pytesseract.pytesseract.tesseract_cmd = r'<full_path_to_your_tesseract_executable>'
For Windows, Path - 'C:\Program Files\Tesseract-OCR\tesseract.exe'
Download and install Tesseract OCR from this link.
In the shell
python OCR_python.py