import bpy
import math

SMALL=0.0001

def nameFlip(name):
    strlen=len(name)
    if(strlen<1):
        return name
    last=name[strlen-1]
    if(last=='R'):
        return name[0:strlen-1]+'L'
    if(last=='L'):
        return name[0:strlen-1]+'R'
    return name
    
def calDistance(v1,v2):
    vx=v1.x-v2.x
    vy=v1.y-v2.y
    vz=v1.z-v2.z
    return math.sqrt(vx*vx+vy*vy+vz*vz)

def getTgt(v,array):
    vcp=v.co.copy()
    vcp.x*=-1
    array.remove(v)
    ret=None
    for tv in array:
        dist=calDistance(vcp,tv.co)
        if(dist<SMALL):
            ret=tv
            array.remove(tv)
            break
    return ret
    

def func():
    index2name={}
    nameflip={}
    obj=bpy.context.active_object
    if(obj.type!='MESH'):
        return
    mesh=obj.data
    for vg in obj.vertex_groups:
        index2name[vg.index]=vg.name
        nameflip[vg.name]=nameFlip(vg.name)
    targets=mesh.vertices.values()
    for v in mesh.vertices:
        if(v.co.x>SMALL):
            tgt=getTgt(v,targets)
            if(tgt==None):
                print("no")
                continue
            for vg in obj.vertex_groups:
                vg.remove([tgt.index])
            vgs=v.groups
            for vge in vgs:
                tvg=obj.vertex_groups[nameflip[index2name[vge.group]]]
                tvg.add([tgt.index],vge.weight,'REPLACE')
                
    
func()