Use PyStage, which bridges the gap between Scratch and Python. This module implements all code blocks as available in Scratch. With the PyStage command line converter, Scratch projects can be easily transferred to Python executable Code. To run your game in Python, PyStage uses PyGame.
Install the module "scratchclient" to access Scratch using Python 3. Do this by going into a terminal or Command Prompt and typing pip install scratchclient. This should download the correct module to access Scratch.