python question! show code and step!

A ranking list provides for each element in the list the position it would hold if the list were sorted in descending order of radius. The maximum entry in the list will have a rank of 1.

For instance, the rank of list [6.0, 5.0, 11.0, 9.0] would be [3, 4, 1, 2].

DO not use numpy. I want to know how [6.0, 5.0, 11.0, 9.0] become [3, 4, 1, 2]

Thanks!