apologies for resurrecting such an old post, but I would like to create a similar thing. However, I am a complete novice when it comes to CGA and scripting. I have followed the tutorials but still struggle.
Your last past did not make any sense to me.
I'd be trying to recreate something like the attached image, but with white lines and the option to add 'open space' islands.
A search of old Geonet posts led to the following, some which have included code:
Parking lot and private street
In general, you'll probably want to use multiple (nested) splits to divide your lot into rows and then into parking spots. Use case statements to choose whether or not to create open spaces.