doc   = __revit__.ActiveUIDocument.Document
uidoc = __revit__.ActiveUIDocument
active_view  = doc.ActiveView
active_level = doc.ActiveView.GenLevel
pt_start = XYZ(30,0,0)
pt_end   = XYZ(30,5,0)
curve    = Line.CreateBound(pt_start, pt_end)
wall = Wall.Create(doc, curve, active_level.Id, False)