python pstuil模块取得cpu使用率、内存使用率、网络状态

#
# Copyright (c) 2014, Lambo Wang, All rights reserved.
# Use of this source code is governed by a GNU v2 license that can be
# found in the LICENSE file.
#  
# Logs: 
# Transplant to NT system by Lambo Wang, 2012-11-28
# Add function of get cpu state and get memory state by Lambo Wang,2012-11-29
# first add to Git of OSChina,2014-10-24 by Lambo Wang  
""" 
Shows real-time NT system statistics. 
Author: Lambo Wang <lambo.wang@icloud.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

#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(time.asctime()+" | "+cpu_state+" | "+memory_state)

# totals
print(" NetStates:")
print("total bytes:   sent: %-10s   received: %s" % (bytes2human(tot_after.bytes_sent),
  bytes2human(tot_after.bytes_recv))
)
print("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("")
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(templ % (name, "TOTAL", "PER-SEC"))
print(templ % (
"bytes-sent",
bytes2human(stats_after.bytes_sent),
bytes2human(stats_after.bytes_sent - stats_before.bytes_sent) + '/s',
))
print(templ % (
"bytes-recv",
bytes2human(stats_after.bytes_recv),
bytes2human(stats_after.bytes_recv - stats_before.bytes_recv) + '/s',
))
print(templ % (
"pkts-sent",
stats_after.packets_sent,
stats_after.packets_sent - stats_before.packets_sent,
))
print(templ % (
"pkts-recv",
stats_after.packets_recv,
stats_after.packets_recv - stats_before.packets_recv,
))
print("")

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