pytesseract tesseract is not installed
#1. Install tesseract using windows installer available at: https://github.com/UB-Mannheim/tesseract/wiki
#2. Note the tesseract path from the installation.Default installation path at the time the time of this edit was: C:UsersUSERAppDataLocalTesseract-OCR. It may change so please check the installation path.
#3. pip install pytesseract
#4. Set the tesseract path in the script before calling image_to_string:
pytesseract.pytesseract.tesseract_cmd = r'C:UsersUSERAppDataLocalTesseract-OCRtesseract.exe'