python执行系统命令后获取返回值的几种方式集合

os.system('ps aux') 

result = os.popen('ps aux')    res = result.read()    for line in res.splitlines():        print line 

p = subprocess.Popen('ps aux',shell=True,stdout=subprocess.PIPE)   out,err = p.communicate()   for line in out.splitlines():     print line 

output = commands.getstatusoutput('ps aux') print output