python输出shell命令执行结果

import os,subprocess
p = subprocess.Popen("df -h", shell=True, stdout=subprocess.PIPE)
out = p.stdout.readlines()

for line in out:
    print line.strip()

　　将df -h的执行结果输出到stdout,再用readlines方法读出来，再print出来

import os,subprocess
x = subprocess.check_output(["date", "+%T"])
print x

　　这个方法可以将某个命令的结果输出到python