Hi Michael,
I'm 99.9% sure that the path to python.exe is correct. (Never 100% sure:-)

For Windows 10:
(Also refered to as command prompt), the command interpreter, Cmd.exe has 10 parameters, 9 of which are "switches":
https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/cmd

A Windows 7 version which might be helpful:
https://sourcedaddy.com/windows-7/using-cmd-switches.html

/c is a switch

I take it that moi.filesystem.shellExecute(...) is running the Windows 10 shellexecute?
(Or some Mac equivalent...?)

The Command Prompt in Windows provides access to over 280 commands:
https://www.lifewire.com/list-of-command-prompt-commands-4092302

- Brian

Also interesting:
https://stackoverflow.com/questions/48437377/cmd-commands-in-shellexecute
Previous link, links to:
https://www.codeproject.com/Articles/5163375/Tiny-CMD