How to modify mainwindow in startup without using .slicerrc.py file

Development
1

We are having script repository in Slicer which we have to keep in executable folder. (So while loading it will do the changes)

But I dont want to use rc file.
Is there any method to call .py file in startup in the EXE. (Hard coded)

2

You could manually edit the NameOfYouAppLauncherSettings.ini file and append --python-script script.py

3 
viewNode = slicer.app.layoutManager().threeDWidget(0).mrmlViewNode()
viewNode.SetBackgroundColor(0,0,0)
viewNode.SetBackgroundColor2(0,0,0)
viewNode.SetBoxVisible(0)
viewNode.SetAxisLabelsVisible(0)

Is there any way to directly use those functions?