Unless somebody has written something in Python I think that you are limited to software like Gardner's QRULE (http://www.umces.edu/al/program/gardner/qrule) or Saura's SIMMAP (http://www2.montes.upm.es/personales/saura/software.html). I have an old aml that will calculate random fractal landscapes, but it is not translated to Python to run in ArcGIS. When I am testing null landscape configurations, I use R to batch QRULE and pass results back to R for analysis.
