python执行系统命令的几种方法

#!/usr/bin/env python

import os,commands

a = os.system('ls /mnt')
print 'a:',a
print '------------------------------'

(status, output) = commands.getstatusoutput('ls /mnt')
print 'status:',status,
print 'output:',output
print '------------------------------'

b = os.popen('ls /mnt')
print b.read()    # b 是一个 function

[root@localhost test]# python cmd.py
a.py	   logstash-patterns-core-master  rhel.repo
conf	   master			  rhel-server-6.5-x86_64-dvd.iso
gems	   nginx-1.9.4			  rsyslog.repo
get_ip.py  patterns			  test.py
hgfs	   rhel				  tqt
a: 0
------------------------------
status: 0 output: a.py
conf
gems
get_ip.py
hgfs
logstash-patterns-core-master
master
nginx-1.9.4
patterns
rhel
rhel.repo
rhel-server-6.5-x86_64-dvd.iso
rsyslog.repo
test.py
tqt
------------------------------
a.py
conf
gems
get_ip.py
hgfs
logstash-patterns-core-master
master
nginx-1.9.4
patterns
rhel
rhel.repo
rhel-server-6.5-x86_64-dvd.iso
rsyslog.repo
test.py
tqt