How to run an existing matlab file from Python ?

Hi All

there is an example question on mathworks on how to run a matlab code from Python, but it doesn't explain how to run an existing m file.

here : first link

import matlab.engine
eng = matlab.engine.start_matlab()
eng.simple_script(nargout=0)
eng.quit()

it is not clear what simple_script is and how I can change to an existing folder.

some explanation here , but it everytime writes the code inside python from scratch :

second link