下面的代码，没有外部库为我工作。我在Python 2.7.9测试

CPU使用率

import os
    
CPU_Pct=str(round(float(os.popen('''grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage }' ''').readline()),2))
print("CPU Usage = " + CPU_Pct)  # print results

和Ram使用，总，使用和免费

import os
mem=str(os.popen('free -t -m').readlines())
"""
Get a whole line of memory output, it will be something like below
['             total       used       free     shared    buffers     cached\n', 
'Mem:           925        591        334         14         30        355\n', 
'-/+ buffers/cache:        205        719\n', 
'Swap:           99          0         99\n', 
'Total:        1025        591        434\n']
 So, we need total memory, usage and free memory.
 We should find the index of capital T which is unique at this string
"""
T_ind=mem.index('T')
"""
Than, we can recreate the string with this information. After T we have,
"Total:        " which has 14 characters, so we can start from index of T +14
and last 4 characters are also not necessary.
We can create a new sub-string using this information
"""
mem_G=mem[T_ind+14:-4]
"""
The result will be like
1025        603        422
we need to find first index of the first space, and we can start our substring
from from 0 to this index number, this will give us the string of total memory
"""
S1_ind=mem_G.index(' ')
mem_T=mem_G[0:S1_ind]
"""
Similarly we will create a new sub-string, which will start at the second value. 
The resulting string will be like
603        422
Again, we should find the index of first space and than the 
take the Used Memory and Free memory.
"""
mem_G1=mem_G[S1_ind+8:]
S2_ind=mem_G1.index(' ')
mem_U=mem_G1[0:S2_ind]

mem_F=mem_G1[S2_ind+8:]
print 'Summary = ' + mem_G
print 'Total Memory = ' + mem_T +' MB'
print 'Used Memory = ' + mem_U +' MB'
print 'Free Memory = ' + mem_F +' MB'

我不相信有一个支持良好的多平台库可用。请记住，Python本身是用C编写的，因此任何库都会像上面建议的那样，对运行哪个特定于操作系统的代码段做出明智的决定。

psutil库提供了各种平台上关于CPU、RAM等的信息:

psutil是一个模块，提供了一个接口，通过使用Python以可移植的方式检索正在运行的进程和系统利用率(CPU，内存)的信息，实现了ps、top和Windows任务管理器等工具提供的许多功能。 它目前支持Linux, Windows, OSX, Sun Solaris, FreeBSD, OpenBSD和NetBSD, 32位和64位架构，Python版本从2.6到3.5 (Python 2.4和2.5的用户可能使用2.1.3版本)。

一些例子:

#!/usr/bin/env python
import psutil
# gives a single float value
psutil.cpu_percent()
# gives an object with many fields
psutil.virtual_memory()
# you can convert that object to a dictionary 
dict(psutil.virtual_memory()._asdict())
# you can have the percentage of used RAM
psutil.virtual_memory().percent
79.2
# you can calculate percentage of available memory
psutil.virtual_memory().available * 100 / psutil.virtual_memory().total
20.8

以下是其他文档，提供了更多的概念和感兴趣的概念:

https://psutil.readthedocs.io/en/latest/

使用psutil库。在Ubuntu 18.04上，pip在2019年1月30日安装了5.5.0(最新版本)。旧版本的行为可能有所不同。 你可以在Python中这样做来检查你的psutil版本:

from __future__ import print_function  # for Python2
import psutil
print(psutil.__versi‌​on__)

获取内存和CPU的统计信息:

from __future__ import print_function
import psutil
print(psutil.cpu_percent())
print(psutil.virtual_memory())  # physical memory usage
print('memory % used:', psutil.virtual_memory()[2])

virtual_memory (tuple)将包含系统范围内使用的内存百分比。对我来说，在Ubuntu 18.04上，这似乎被高估了几个百分点。

你也可以得到当前Python实例所使用的内存:

import os
import psutil
pid = os.getpid()
python_process = psutil.Process(pid)
memoryUse = python_process.memory_info()[0]/2.**30  # memory use in GB...I think
print('memory use:', memoryUse)

它给出了Python脚本的当前内存使用情况。

pypi页面上有一些更深入的psutil示例。

@CodeGench的解决方案不需要外壳，所以假设Linux和Python的标准库:

def cpu_load(): 
    with open("/proc/stat", "r") as stat:
        (key, user, nice, system, idle, _) = (stat.readline().split(None, 5))
    assert key == "cpu", "'cpu ...' should be the first line in /proc/stat"
    busy = int(user) + int(nice) + int(system)
    return 100 * busy / (busy + int(idle))

从第一反应中获得反馈，并做一些小的改变

#!/usr/bin/env python
#Execute commond on windows machine to install psutil>>>>python -m pip install psutil
import psutil

print ('                                                                   ')
print ('----------------------CPU Information summary----------------------')
print ('                                                                   ')

# gives a single float value
vcc=psutil.cpu_count()
print ('Total number of CPUs :',vcc)

vcpu=psutil.cpu_percent()
print ('Total CPUs utilized percentage :',vcpu,'%')

print ('                                                                   ')
print ('----------------------RAM Information summary----------------------')
print ('                                                                   ')
# you can convert that object to a dictionary 
#print(dict(psutil.virtual_memory()._asdict()))
# gives an object with many fields
vvm=psutil.virtual_memory()

x=dict(psutil.virtual_memory()._asdict())

def forloop():
    for i in x:
        print (i,"--",x[i]/1024/1024/1024)#Output will be printed in GBs

forloop()
print ('                                                                   ')
print ('----------------------RAM Utilization summary----------------------')
print ('                                                                   ')
# you can have the percentage of used RAM
print('Percentage of used RAM :',psutil.virtual_memory().percent,'%')
#79.2
# you can calculate percentage of available memory
print('Percentage of available RAM :',psutil.virtual_memory().available * 100 / psutil.virtual_memory().total,'%')
#20.8