internal.py

                point.select_left_handle = point.select_control_point = point.select_right_handle = True
        elif spline.type == 'POLY':
            for point in spline.points:
                point.select = True
    splines_at_layer = [splines]
    for i in range(1, count):
        bpy.ops.curve.duplicate()
        bpy.ops.transform.translate(value=offset)
        splines_at_layer.append(getSelectedSplines(True, True))
        if serpentine:
            bpy.ops.curve.switch_direction()
    if connect:
        for i in range(1, count):
            prev_layer = splines_at_layer[i-1]
            next_layer = splines_at_layer[i]
            for j in range(0, len(next_layer)):
                bpy.ops.curve.select_all(action='DESELECT')
                if prev_layer[j].type == 'POLY':
                    prev_layer[j].points[-1].select = True
                else:
                    prev_layer[j].bezier_points[-1].select_control_point = True
                if next_layer[j].type == 'POLY':
                    next_layer[j].points[0].select = True
                else:
                    next_layer[j].bezier_points[0].select_control_point = True
                bpy.ops.curve.make_segment()
    bpy.ops.curve.select_all(action='DESELECT')