如何在python中扫描脚本以查找上层脚本的返回值？

Question

import os

import pdb

os.system("ToBuildOrNot.py MSS_sims")

for output in os.system:

     if ToBuildOrNot is True:

         print "The MSS_sims Needs To rebuilt"

     elif ToBuildOrNot is False:

         print "The MSS_sism does NOT Need to be Rebuilt"

     else:

         print "error"