Selects elements that are symmetrical to the current selection.

selectSymmetrical.py

#!/usr/bin/env python

import lx
import lxifc
import lxu.command

class GetSymmetricalVertex(lxifc.Visitor):
	def __init__(self, accessor):
		self.accessor = accessor
		self.sym_ids = set()

	def vis_Evaluate(self):
		try:
			if not self.accessor.OnSymmetryCenter():
				sym = self.accessor.Symmetry()
				if sym:
					self.sym_ids.add(sym)
		except:
			pass

class GetSymmetricalEdge(lxifc.Visitor):
	def __init__(self, accessor):
		self.accessor = accessor
		self.sym_ids = set()

	def vis_Evaluate(self):
		try:
			if not self.accessor.OnSymmetryCenter():
				sym = self.accessor.Symmetry()
				if sym:
					self.accessor.Select(sym)
					self.sym_ids.add(self.accessor.Endpoints())
		except:
			pass

class GetSymmetricalPolygon(lxifc.Visitor):
	def __init__(self, accessor):
		self.accessor = accessor
		self.sym_ids = set()

	def vis_Evaluate(self):
		try:
			sym = self.accessor.Symmetry()
			if sym:
				self.sym_ids.add(sym)
		except:
			pass

class SelectSymmetrical_Cmd(lxu.command.BasicCommand):
	def __init__(self):
		lxu.command.BasicCommand.__init__ (self)

	def cmd_Interact(self):
		pass

	def cmd_UserName(self):
		return 'Select Symmetrical'

	def cmd_Desc(self):
		return 'Selects elements that are symmetrical to the current selection.'

	def cmd_Tooltip(self):
		return 'Selects elements that are symmetrical to the current selection.'

	def cmd_Help(self):
		return 'http://www.farfarer.com/'

	def basic_ButtonName(self):
		return 'Select Symmetrical'

	def cmd_Flags(self):
		return lx.symbol.fCMD_SELECT | lx.symbol.fCMD_MODEL | lx.symbol.fCMD_UNDO

	def basic_Enable(self, msg):
		return True

	def basic_Execute(self, msg, flags):
		sel_svc = lx.service.Selection()
		mesh_svc = lx.service.Mesh()
		layer_svc = lx.service.Layer()

		mode = mesh_svc.ModeCompose('select', 'hide lock')

		layer_scan = lx.object.LayerScan(layer_svc.ScanAllocate(lx.symbol.f_LAYERSCAN_ACTIVE | lx.symbol.f_LAYERSCAN_MARKALL))

		if not layer_scan.test():
			return

		types = lx.object.storage('i', 4)
		types.set((lx.symbol.iSEL_VERTEX, lx.symbol.iSEL_EDGE, lx.symbol.iSEL_POLYGON, 0))
		currentType = sel_svc.CurrentType(types)

		sel_svc.StartBatch ()

		for l in xrange(layer_scan.Count()):
			mesh = lx.object.Mesh (layer_scan.MeshBase (l))

			point = lx.object.Point (mesh.PointAccessor ())
			edge = lx.object.Edge (mesh.EdgeAccessor ())
			polygon = lx.object.Polygon (mesh.PolygonAccessor ())
			if not point.test () or not edge.test () or not polygon.test ():
				continue

			if currentType == lx.symbol.iSEL_VERTEX:
				getSymVertex = GetSymmetricalVertex(point)
				point.Enumerate(mode, getSymVertex, 0)

				sel_type_vertex = sel_svc.LookupType (lx.symbol.sSELTYP_VERTEX)
				vertex_pkt_trans = lx.object.VertexPacketTranslation (sel_svc.Allocate(lx.symbol.sSELTYP_VERTEX))
				for vertex_id in getSymVertex.sym_ids:
					sel_svc.Select (lx.symbol.iSEL_VERTEX, vertex_pkt_trans.Packet (vertex_id, 0, mesh))

			elif currentType == lx.symbol.iSEL_EDGE:
				getSymEdge = GetSymmetricalEdge(edge)
				edge.Enumerate(mode, getSymEdge, 0)

				sel_type_edge = sel_svc.LookupType (lx.symbol.sSELTYP_EDGE)
				edge_pkt_trans = lx.object.EdgePacketTranslation (sel_svc.Allocate(lx.symbol.sSELTYP_EDGE))
				for edge_id in getSymEdge.sym_ids:
					sel_svc.Select (lx.symbol.iSEL_EDGE, edge_pkt_trans.Packet (edge_id[0], edge_id[1], 0, mesh))

			elif currentType == lx.symbol.iSEL_POLYGON:
				getSymPolygon = GetSymmetricalPolygon(polygon)
				polygon.Enumerate(mode, getSymPolygon, 0)

				polygon_pkt_trans = lx.object.PolygonPacketTranslation (sel_svc.Allocate(lx.symbol.sSELTYP_POLYGON))
				print getSymPolygon.sym_ids
				for poly_id in getSymPolygon.sym_ids:
					sel_svc.Select (lx.symbol.iSEL_POLYGON, polygon_pkt_trans.Packet (poly_id, mesh))

		layer_scan.Apply()

		sel_svc.EndBatch ()

lx.bless(SelectSymmetrical_Cmd, 'ffr.selectSymmetrical')

Hi!
Script error((
MODO version 12v1

Hope this helps You.
Tnx!