A "Selection" is a collection of entities (lines, faces, etc.) In order to get the line, you have to get the first object in the Selection, since you only have one thing selected: line = selection[0] Then, once you have the line, you can get the start and end vertices like this: vtxStart = line.start vtxEnd = line.end To get the positions of the vertices, just type either: startPosition = vtxStart.position or endPosition = vtxEnd.position Hopefully this is clear enough to get you started.