Error when executing operator

A RapidMiner user wants to know the answer to this question: "Hey there. When I try to use the Execute Python operator it is giving error saying Failed to detect Python at the given path. I do have Python installed on my computer. Maybe someone knows how to fix this? I want to restrict to sample size of clustering are there any other options to do so? F.e i have 3 cluster and 20 item i wanna that each cluster have 6 item at least or max. 10 item how can i restrict it ? Thank you."