How to determine point and circle (or curve) closest distance in 3D?

How is it possible to determine in 3D the closest distance of a point from a circle with python?
Actually a circle is a curve so generally is there any way to get the distance of a point from a curve?
In Rhino3D there’s a CurvePointDistance function for that, which works great but I’ve couldn’t find any similar in Blender. (I suppose I need to write one in python…)

Thanks!