Python獲取CPU使用率、內存使用率、網絡使用狀態
注：需要安裝psutil庫

#!/usr/bin/env python
#

$Id: iotop.py 1160 2011-10-14 18:50:36Z g.rodola@gmail.com $
#
Copyright (c) 2009, Jay Loden, Giampaolo Rodola'. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
Transplant to NT system by hui.wang, 2012-11-28
Add function of get cpu state and get memory state by hui.wang,2012-11-29
"""
Shows real-time network statistics.
Author: Giampaolo Rodola' <g.rodola@gmail.com>
"""
import sys
import os
import atexit
import time
import psutil
print "Welcome,current system is",os.name," 3 seconds late start to get data..."
time.sleep(3)
line_num = 1
def print_line(str):
    print str
function of Get CPU State
def getCPUstate(interval=1):
    return (" CPU: " + str(psutil.cpu_percent(interval)) + "%")
function of Get Memory
def getMemorystate():
    phymem = psutil.phymem_usage()
    buffers = getattr(psutil, 'phymem_buffers', lambda: 0)()
    cached = getattr(psutil, 'cached_phymem', lambda: 0)()
    used = phymem.total - (phymem.free + buffers + cached)
    line = " Memory: %5s%% %6s/%s" % (
        phymem.percent,
        str(int(used / 1024 / 1024)) + "M",
        str(int(phymem.total / 1024 / 1024)) + "M"
    )

    return line
def bytes2human(n):
    """
    >>> bytes2human(10000)
    '9.8 K'
    >>> bytes2human(100001221)
    '95.4 M'
    """
    symbols = ('K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y')
    prefix = {}
    for i, s in enumerate(symbols):
        prefix[s] = 1 << (i+1)*10
    for s in reversed(symbols):
        if n >= prefix[s]:
            value = float(n) / prefix[s]
            return '%.2f %s' % (value, s)
    return '%.2f B' % (n)
def poll(interval):
    """Retrieve raw stats within an interval window."""
    tot_before = psutil.network_io_counters()
    pnic_before = psutil.network_io_counters(pernic=True)

# sleep some time
time.sleep(interval)
tot_after = psutil.network_io_counters()
pnic_after = psutil.network_io_counters(pernic=True)
# get cpu state
cpu_state = getCPUstate(interval)
# get memory
memory_state = getMemorystate()
return (tot_before, tot_after, pnic_before, pnic_after,cpu_state,memory_state)





def refresh_window(tot_before, tot_after, pnic_before, pnic_after,cpu_state,memory_state):
    os.system("cls")
    """Print stats on screen."""

#print current time #cpu state #memory
print_line(time.asctime()+" | "+cpu_state+" | "+memory_state)

# totals
print_line(" NetStates:")
print_line("total bytes:           sent: %-10s   received: %s" \
      % (bytes2human(tot_after.bytes_sent),
         bytes2human(tot_after.bytes_recv))
)
print_line("total packets:         sent: %-10s   received: %s" \
      % (tot_after.packets_sent, tot_after.packets_recv)
)




# per-network interface details: let's sort network interfaces so
# that the ones which generated more traffic are shown first
print_line("")
nic_names = pnic_after.keys()
nic_names.sort(key=lambda x: sum(pnic_after[x]), reverse=True)
for name in nic_names:
    stats_before = pnic_before[name]
    stats_after = pnic_after[name]
    templ = "%-15s %15s %15s"
    print_line(templ % (name, "TOTAL", "PER-SEC"))
    print_line(templ % (
        "bytes-sent",
        bytes2human(stats_after.bytes_sent),
        bytes2human(stats_after.bytes_sent - stats_before.bytes_sent) + '/s',
    ))
    print_line(templ % (
        "bytes-recv",
        bytes2human(stats_after.bytes_recv),
        bytes2human(stats_after.bytes_recv - stats_before.bytes_recv) + '/s',
    ))
    print_line(templ % (
        "pkts-sent",
        stats_after.packets_sent,
        stats_after.packets_sent - stats_before.packets_sent,
    ))
    print_line(templ % (
        "pkts-recv",
        stats_after.packets_recv,
        stats_after.packets_recv - stats_before.packets_recv,
    ))
    print_line("")





try:
    interval = 0
    while 1:
        args = poll(interval)
        refresh_window(*args)
        interval = 1
except (KeyboardInterrupt, SystemExit):
    pass</pre>