list nconstraint components

selected = cmds.ls(sl=1)

custom_nconst_data = {}
for nconst in selected:
    custom_nconst_data[nconst] = []
    for a in cmds.ls(nconst+'.componentIds[*]'):
        for ncomp in cmds.listConnections(a):
            indices = cmds.ls(ncomp+'.ci[*]')
            nobj = cmds.listConnections(ncomp+'.objectId')
            mesh = cmds.listConnections(nobj[0]+'.inputMesh')
            vtx_list = [mesh[0]+'.vtx[{}]'.format(str(cmds.getAttr(i))) for i in indices]
            if vtx_list==[]:
                custom_nconst_data[nconst].extend(mesh)
            else:
                custom_nconst_data[nconst].extend(vtx_list)

            custom_nconst_data[nconst] += vtx_list
print custom_nconst_data