[NEST Users] structural_plasticity.py change connection rules

I'm running the structural_plasticity.py example and would like to make some modifications. I was able to change the initial Ca value with the help of Charl. Now I'm trying to specify connection rules such as disallowing autapses. Does anyone have any suggestions on how I can implement this in the structural plasticity example? I'm not CS major but I am able to compile and run nest locally.