Version for ArcGIS Pro (Python 3). A version for ArcGIS Desktop (Python 2.x) is available here: https://github.com/ZGIS/ZonalMetrics-Toolbox
How to cite and background information:
Adamczyk, J., Tiede, D., 2017. ZonalMetrics - a Python toolbox for zonal landscape structure analysis. Computers & Geosciences 99, 91–99. DOI:10.1016/j.cageo.2016.11.005 http://www.sciencedirect.com/science/article/pii/S0098300416306586