blend_shape_export.py

from pymel.core import *

source, result = selected()
source = source.getShape()
bs = source.inMesh.inputs()[0]

for i in range(bs.getWeightCount()):
    bs.setWeight(i, 0)
out_parent = createNode('transform', name=result.name()+'_blendShapes')

for i, name in enumerate(bs.getTarget()):
    out_name = name.rsplit('|')[-1]
    bs.setWeight(i, 1)    
    new = duplicate(result, ic=False)[0]
    new.setParent(out_parent)
    new.rename(out_name)
    bs.setWeight(i, 0)