獲取linux的剩餘cpu

在linux中直接使用“top”命令查詢：第三行就是關於CPU的信息

[root@CTDI testzq]# top
top - 22:03:22 up 12 days, 10:13,  2 users,  load average: 0.23, 0.23, 0.25
Tasks: 178 total,   1 running, 177 sleeping,   0 stopped,   0 zombie
%Cpu(s):  8.8 us,  0.3 sy,  0.0 ni, 91.4 id,  0.0 wa,  0.0 hi,  0.1 si,  0.0 st
KiB Mem : 16268356 total,  2715284 free,  6874236 used,  6678836 buff/cache
KiB Swap:  8388604 total,  8369176 free,    19428 used.  8640692 avail Mem


  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
1733 mysql     20   0 2646916 442212   8356 S  27.7  2.7   3696:03 mysqld
7230 ctdi      20   0  752312  67788   5376 S   0.7  0.4   1:12.49 python

import os
import re  

def get_cpuinfo():
   cpupercent=0
   liststr = os.popen('top -bi -n 1').read().split('\n')[2]              #第三行：%Cpu(s):  8.0 us,  0.5 sy,  0.0 ni, 91.4 id,  0.0 wa,  0.0 hi,  0.1 si,  0.0 st

   cpudata = re.findall(r'-?\d+\.?\d*e?-?\d*?',liststr)                  #['8.0', '0.5', '0.0', '91.4', '0.0', '0.0', '0.1', '0.0'] 
   cpupercent = 100 - eval(cpudata[3])
   return  cpupercent
print(get_cpuinfo())