python 查询windows的cpu、内存使用率

# -*- coding: UTF-8 -*-
import os

def get_info(metric):
    metric_cmd_map = {
        "cpu_usage_rate": "wmic cpu get loadpercentage",
        "mem_total": "wmic ComputerSystem get TotalPhysicalMemory",
        "mem_free": "wmic OS get FreePhysicalMemory"
    }
    out = os.popen("{}".format(metric_cmd_map.get(metric)))
    value = out.read().split("\n")[2]
    out.close()
    return float(value)

# cpu使用率
cpu_usage_rate = get_info('cpu_usage_rate')
print("windows的CPU使用率是{}%".format(cpu_usage_rate))

# 无法直接查出内存使用率，总内存单位是b，而剩余内存单位是kb
mem_total = get_info('mem_total')/1024
mem_free = get_info('mem_free')
mem_usage_rate = (1 - mem_free/mem_total)*100
print("windows的内存使用率是{}%".format(mem_usage_rate))