partial class Examples
{
  public static Result OffsetCurve(RhinoDoc doc)
  {
    ObjRef obj_ref;
    var rs = RhinoGet.GetOneObject(
      "Select Curve", false, ObjectType.Curve, out obj_ref);
    if (rs != Result.Success)
      return rs;
    var curve = obj_ref.Curve();
    if (curve == null)
      return Result.Nothing;

    Point3d point;
    rs = RhinoGet.GetPoint("Select Side", false, out point);
    if (rs != Result.Success)
      return rs;
    if (point == Point3d.Unset)
      return Result.Nothing;

    var curves = curve.Offset(point, Vector3d.ZAxis, 1.0,
      doc.ModelAbsoluteTolerance, CurveOffsetCornerStyle.None);

    foreach (var offset-curve in curves)
      doc.Objects.AddCurve(offset-curve);

    doc.Views.Redraw();
    return Result.Success;
  }
}

from Rhino.DocObjects import ObjectType
from Rhino.Geometry import Point3d, Vector3d, CurveOffsetCornerStyle
from Rhino.Input import RhinoGet
from Rhino.Commands import Result
from scriptcontext import doc
import rhinoscriptsyntax as rs
import System

def RunCommand():
    rc, obj_ref = RhinoGet.GetOneObject("Select Curve", False, ObjectType.Curve)
    if rc != Result.Success:
        return rc
    curve = obj_ref.Curve()
    if curve == None:
        return Result.Nothing

    rc, point = RhinoGet.GetPoint("Select Side", False)
    if rc != Result.Success:
        return rc
    if point == Point3d.Unset:
        return Result.Nothing

    curves = curve.Offset(point, Vector3d.ZAxis, 1.0, doc.ModelAbsoluteTolerance, System.Enum.Parse(CurveOffsetCornerStyle, "None"))

    for offset_curve in curves:
        doc.Objects.AddCurve(offset_curve)

    doc.Views.Redraw()
    return Result.Success

if __name__ == "__main__":
    RunCommand()