获取进程cpu占用

#!/usr/bin/env python
import math
import time

while 1:
#########time1
        total1_cpu = []
        total2_cpu = []
        with open('/proc/[pid]/stat','r') as f:
            context = f.readline().split(' ')

        with open('/proc/stat','r') as f:
                context_total = f.readline()

        for item in context_total.split(' ')[2:]:
                total1_cpu.append(eval(item))
        total_cpu_sum1 = sum(total1_cpu)

        user_cpu1 = float(context[13])
        sys_cpu1 = float(context[14])
        cutime1 = float(context[15])
        cstime1 = float(context[16])
        process_total_time1 = user_cpu1 + sys_cpu1 + cutime1 + cstime1

#print(total_cpu_sum1,user_cpu1,sys_cpu1)

        time.sleep(1)

#########time2

        with open('/proc/6443/stat','r') as f:
                context = f.readline().split(' ')

        with open('/proc/stat','r') as f:
                context_total = f.readline()

        for item in context_total.split(' ')[2:]:
                total2_cpu.append(eval(item))
        total_cpu_sum2 = sum(total2_cpu)

        user_cpu2 = float(context[13])
        sys_cpu2 = float(context[14])
        cutime2 = float(context[15])
        cstime2 = float(context[16])
        process_total_time2 = user_cpu2 + sys_cpu2 + cutime2 + cstime2

        cpu_usage = ((process_total_time2 - process_total_time1)/(total_cpu_sum2 - total_cpu_sum1)) * 100 * 2  # *2 The number of CPUs
        print("%.2f"%cpu_usage)

参考：http://blog.csdn.net/cybertan/article/details/7596633

        http://www.linuxhowtos.org/manpages/5/proc.htm