Hi Brian, does it behave any better if you pass the parameters as the second argument to moi.filesystem.shellExecute() ?

Something like this:

var res = moi.filesystem.shellExecute( 'C:\\Users\\orcha\\AppData\\Local\\Programs\\Python\\Python39\\python', 'sys.stdout.write("I am a test")', true );
if ( res.output ) moi.ui.alert( res.output );

- Michael