# Convex hull spanning n-percent of points

I would like to calculate the convex hull of some points, but neglect some "outlier" points. I.e. in the end i would like to have the convex hull spanning, let's say, 90% of the points instead of all. How would I best do that, is there a known algorithm for that? And if yes, can I even hope for a Python implementation? Thanks a lot.