python 调用 DOS命令 得到命令提示及结果

import os,time,re,sys,subprocess
os.chdir('F:\wifi\hashcat-6.2.5\hashcat-6.2.5')
ab='hashcat -m 22000 BCD1.hc22000 -a 3 ?d?d?d?d?d?d?d?d -w 3  -D 2 -O --session=myx1 -o muxx.txt'
jieguo="INFO: All hashes found in potfile"
av=['-a 3 ?d?d?d?d?d?d?d?d','-a 3 ?d?d?d?d?d?d?d?d?d','-a 1 xing1.dic riqi.dic']
for iv in av:
    am='hashcat -m 22000 BCD1.hc22000 '+iv+' -w 3  -D 2 -O --session=myx1 -o muxx.txt'
    rea=os.popen(am)
    rex=rea.read()
    if jieguo in rex:
        break