简介

psutil是一个开源切跨平台的库，其提供了便利的函数用来获取才做系统的信息，比如CPU，内存，磁盘，网络等。此外，psutil还可以用来进行进程管理，包括判断进程是否存在、获取进程列表、获取进程详细信息等。而且psutil还提供了许多命令行工具提供的功能，包括：ps，top，lsof，netstat，ifconfig， who，df，kill，free，nice，ionice，iostat，iotop，uptime，pidof，tty，taskset，pmap。

psutil是一个跨平台的库，在官方网站上查到其支持如下操作系统。

• Linux
• Windows
• OSX
• FreeBSD
• OpenBSD
• NetBSD
• Sun Solaris
• AIX

Works with Python versions from 2.6 to 3.X.

psutil包含了异常、类、功能函数和常量，其中功能函数用来获取系统的信息，如CPU、磁盘、内存、网络等。类用来实现进程的管理功能

功能函数

根据函数的功能，主要分为CPU、磁盘、内存、网络几类，下面将会总几个方面来介绍psutil提供的功能函数。

CPU相关：

# 查看cpu个数
>>> import psutil
>>> psutil.cpu_count()
2
>>> psutil.cpu_count(logical=False)
1
>>> 
# 查看cpu利用率
>>> psutil.cpu_percent()
0.2
>>> psutil.cpu_percent(percpu=True)
[0.1, 0.2]
>>> 
# 查看cpu时间花费
>>> psutil.cpu_times()
scputimes(user=29.09, nice=0.0, system=22.62, idle=24434.77, iowait=1.74, irq=0.0, softirq=0.28, steal=0.27, guest=0.0, guest_nice=0.0)
>>> psutil.cpu_times(percpu=True)
[scputimes(user=13.64, nice=0.0, system=12.02, idle=12235.5, iowait=1.0, irq=0.0, softirq=0.16, steal=0.09, guest=0.0, guest_nice=0.0), 
scputimes(user=15.47, nice=0.0, system=10.62, idle=12229.44, iowait=0.74, irq=0.0, softirq=0.12, steal=0.17, guest=0.0, guest_nice=0.0)]
>>> print(cpu_time)
scputimes(user=29.24, nice=0.0, system=22.76, idle=24618.94, iowait=1.74, irq=0.0, softirq=0.28, steal=0.27, guest=0.0, guest_nice=0.0)
>>> cpu_time.user
29.24

Memory内存相关:

virtual_memory()：以命名元组的形式返回内存使用情况，包括总内存，可用内存，内存利用率，buffer和cache等。单位为字节。

>>> import psutil
>>> psutil.virtual_memory()
svmem(total=8071716864, available=6532554752, percent=19.1, used=1258717184, free=6526308352, active=1153519616, inactive=194592768, buffers=2129920, cached=284561408, shared=9011200, slab=39006208)

---

swap_memory()：以命名元组的形式返回swap/memory使用情况，包含swap中页的换入和换出。

>>> import psutil
>>> psutil.swap_memory()
sswap(total=17179865088, used=0, free=17179865088, percent=0.0, sin=0, sout=0)
>>> 

单位转换

import psutil
def bytes2human(n):
     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 '%.1f%s' % (value,s)
     return '%sB' % n
print(bytes2human(psutil.virtual_memory().total))

Disk相关：

# 查看所有已挂在的磁盘
>>> psutil.disk_partitions()
[sdiskpart(device='/dev/vda3', mountpoint='/', fstype='xfs', opts='rw,relatime,attr2,inode64,noquota'), sdiskpart(device='/dev/vda6', mountpoint='/data1', fstype='xfs', opts='rw,relatime,attr2,inode64,noquota'), sdiskpart(device='/dev/vda2', mountpoint='/boot', fstype='xfs', opts='rw,relatime,attr2,inode64,noquota')]
# 使用列表表达式查询指定挂载点信息
>>> [device for device in psutil.disk_partitions() if device.mountpoint == '/']
[sdiskpart(device='/dev/vda3', mountpoint='/', fstype='xfs', opts='rw,relatime,attr2,inode64,noquota')]
>>> 
# 查看磁盘使用情况
>>> psutil.disk_usage('/')
sdiskusage(total=85857402880, used=3858100224, free=81999302656, percent=4.5)
# 查看磁盘io统计汇总
>>> psutil.disk_io_counters()
sdiskio(read_count=6828, write_count=3878, read_bytes=273637888, write_bytes=30182912, read_time=6870, write_time=2079, read_merged_count=7, write_merged_count=126, busy_time=4841)
# 分别列出单个磁盘的统计信息
>>> psutil.disk_io_counters(perdisk=True)
{'vda': sdiskio(read_count=6828, write_count=3878, read_bytes=273637888, write_bytes=30182912, read_time=6870, write_time=2079, read_merged_count=7, write_merged_count=126, busy_time=4841), 'vda1': sdiskio(read_count=34, write_count=0, read_bytes=139264, write_bytes=0, read_time=1, write_time=0, read_merged_count=0, write_merged_count=0, busy_time=1), 'vda2': sdiskio(read_count=1934, write_count=2049, read_bytes=22754816, write_bytes=2097152, read_time=570, write_time=801, read_merged_count=0, write_merged_count=0, busy_time=1347), 'vda3': sdiskio(read_count=4009, write_count=1729, read_bytes=187268608, write_bytes=12412416, read_time=5302, write_time=911, read_merged_count=4, write_merged_count=115, busy_time=3114), 'vda4': sdiskio(read_count=6, write_count=0, read_bytes=18432, write_bytes=0, read_time=1, write_time=0, read_merged_count=0, write_merged_count=0, busy_time=1), 'vda5': sdiskio(read_count=48, write_count=0, read_bytes=2248704, write_bytes=0, read_time=13, write_time=0, read_merged_count=0, write_merged_count=0, busy_time=9), 'vda6': sdiskio(read_count=763, write_count=100, read_bytes=60118528, write_bytes=15673344, read_time=948, write_time=367, read_merged_count=3, write_merged_count=11, busy_time=459), 'sr0': sdiskio(read_count=0, write_count=0, read_bytes=0, write_bytes=0, read_time=0, write_time=0, read_merged_count=0, write_merged_count=0, busy_time=0)}

Network相关：

# 查看网卡信息统计
>>> psutil.net_io_counters()
snetio(bytes_sent=9699431, bytes_recv=1895536, packets_sent=8606, packets_recv=27354, errin=0, errout=0, dropin=0, dropout=0)
# 查看网卡配置信息
>>> psutil.net_if_addrs()
{'lo': [snicaddr(family=<AddressFamily.AF_INET: 2>, address='127.0.0.1', netmask='255.0.0.0', broadcast=None, ptp=None), snicaddr(family=<AddressFamily.AF_INET6: 10>, address='::1', netmask='ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff', broadcast=None, ptp=None), snicaddr(family=<AddressFamily.AF_PACKET: 17>, address='00:00:00:00:00:00', netmask=None, broadcast=None, ptp=None)], 'eth0': [snicaddr(family=<AddressFamily.AF_INET: 2>, address='172.16.5.12', netmask='255.255.255.0', broadcast='172.16.5.255', ptp=None), snicaddr(family=<AddressFamily.AF_INET6: 10>, address='fe80::9700:20da:ed33:9f50%eth0', netmask='ffff:ffff:ffff:ffff::', broadcast=None, ptp=None), snicaddr(family=<AddressFamily.AF_PACKET: 17>, address='52:54:00:3d:ea:06', netmask=None, broadcast='ff:ff:ff:ff:ff:ff', ptp=None)]}
>>> a = psutil.net_if_addrs()
>>> a['eth0']
[snicaddr(family=<AddressFamily.AF_INET: 2>, address='172.16.5.12', netmask='255.255.255.0', broadcast='172.16.5.255', ptp=None), snicaddr(family=<AddressFamily.AF_INET6: 10>, address='fe80::9700:20da:ed33:9f50%eth0', netmask='ffff:ffff:ffff:ffff::', broadcast=None, ptp=None), snicaddr(family=<AddressFamily.AF_PACKET: 17>, address='52:54:00:3d:ea:06', netmask=None, broadcast='ff:ff:ff:ff:ff:ff', ptp=None)]
>>> a['eth0'][0]
snicaddr(family=<AddressFamily.AF_INET: 2>, address='172.16.5.12', netmask='255.255.255.0', broadcast='172.16.5.255', ptp=None)
>>> a['eth0'][0][1]
'172.16.5.12'
# 查看当前登录用户信息
>>> psutil.users()
[suser(name='root', terminal='pts/0', host='172.16.2.66', started=1574151552.0, pid=1437), suser(name='root', terminal='pts/1', host='172.16.2.66', started=1574161536.0, pid=1699)]
>>> 

进程管理

psutil还提供了作为进程管理的功能函数，包括获取进程列表，判断是否存在。

进程相关信息的方法：

• name：获取进程的名称
• cmdline：获取启动进程的命令行参数
• create_time：获取进程的创建时间(时间戳格式)
• num_fds：进程打开的文件个数
• num_threads：进程的子进程个数
• is_running：判断进程是否正在运行
• send_signal：给进程发送信号，类似与os.kill等
• kill：发送SIGKILL信号结束进程
• terminate：发送SIGTEAM信号结束进程

# 以列表形式查看正在运行的进程
>>> psutil.pids()
[1, 2, 3, 5, 7, 8, 9, 10, 11, 12, 13, 14, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 32, 33, 34, 35, 43, 44, 45, 46, 47, 48, 61, 93, 99, 233, 234, 236, 237, 238, 242, 244, 245, 260, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 346, 374, 377, 378, 497, 498, 499, 500, 501, 502, 503, 506, 508, 509, 510, 511, 512, 513, 514, 515, 612, 616, 636, 638, 639, 640, 641, 643, 646, 647, 655, 658, 661, 677, 688, 689, 901, 902, 903, 912, 925, 949, 977, 981, 992, 994, 995, 997, 1001, 1002, 1003, 1004, 1255, 1536, 1840, 1842, 1844, 1861, 1862, 1863, 1864]
# 查看进程运行状态，以布尔形式显示
>>> psutil.pid_exists(1)
True
# 迭代当前正在运行进程，查看列表中前三个实例的信息
>>> list(psutil.process_iter())[:3]
[psutil.Process(pid=1, name='systemd', started='16:19:47'), psutil.Process(pid=2, name='kthreadd', started='16:19:47'), psutil.Process(pid=3, name='ksoftirqd/0', started='16:19:47')]
>>> 
# 通过进程号实例化对象
>>> process = psutil.Process(1)
>>> print(process)
psutil.Process(pid=1, name='systemd', started='16:19:47')
# 获取进程的名称
>>> process.name()
'systemd'
>>> process.create_time()
1574151587.05
>>> process.num_fds()
47
>>> process.num_threads()
1
>>>