blendshape mirror

gistfile1.py

import maya.cmds as cmds
import maya.mel as mel

def mirrorBlendshape(targets, originalinal):
    original = cmds.ls(selection=True)[-1]
    targets = cmds.ls(selection=True)[:-1]
    
    mirror = cmds.duplicate(original)[0]
    bldShp = cmds.blendShape(targets,mirror)[0]
    try:
        cmds.setAttr(mirror + '.sx', lock=False)
    except:
        pass
    cmds.setAttr(mirror + '.sx', -1)
    
    mirrorTrg = cmds.duplicate(original)[0]
    cmds.select(mirrorTrg,mirror)
    mel.eval('CreateWrap;')
    
    mirrorTrgs = []
    for trg in targets:
        cmds.setAttr('%s.%s' % (bldShp, trg), 1)
        temp = cmds.duplicate(mirrorTrg)[0]
        temp = cmds.rename(temp, trg)
        mirrorTrgs.append(temp)
        cmds.setAttr('%s.%s' % (bldShp, trg), 0)
    
    cmds.delete(mirror)
    cmds.delete(mirrorTrg)
    return mirrorTrgs


targets = cmds.ls(selection=True)[:-1]
orig = cmds.ls(selection=True)[-1]
mirrorBlendshape(targets,orig)