运维离不开对系统信息的监控，比如CPU利用率、内存占用、网络、流程等相关信息需要监控。虽然我们可以通过操作系统提供的任务管理器或命令查看相关信息，但这些日常操作和维护任务仍然无法简化。如果我们通过编写程序获取上述信息，系统信息监控是一项简单易行的工作。
在Python获取系统信息最方便的模块是psutil（process and systemutilities）。系统相关信息可以通过几行代码获取，也是跨平台库。

>>> import psutil >>> >>> psutil.cpu_times() scputimes(user=3961.46, nice=169.729, system=2150.659, idle=16900.540, iowait=629.59, irq=0.0, softirq=19.42, steal=0.0, guest=0, nice=0.0) >>> >>> for x in range(3): ...     psutil.cpu_percent(interval=1) ... 4.0 5.9 3.8 >>> >>> for x in range(3): ...     psutil.cpu_percent(interval=1, percpu=True)
...
[4.0, 6.9, 3.7, 9.2]
[7.0, 8.5, 2.4, 2.1]
[1.2, 9.0, 9.9, 7.2]
>>>
>>> for x in range(3):
...     psutil.cpu_times_percent(interval=1, percpu=False)
...
scputimes(user=1.5, nice=0.0, system=0.5, idle=96.5, iowait=1.5, irq=0.0, softirq=0.0, steal=0.0, guest=0.0, guest_nice=0.0)
scputimes(user=1.0, nice=0.0, system=0.0, idle=99.0, iowait=0.0, irq=0.0, softirq=0.0, steal=0.0, guest=0.0, guest_nice=0.0)
scputimes(user=2.0, nice=0.0, system=0.0, idle=98.0, iowait=0.0, irq=0.0, softirq=0.0, steal=0.0, guest=0.0, guest_nice=0.0)
>>>
>>> psutil.cpu_count()
4
>>> psutil.cpu_count(logical=False)
2
>>>
>>> psutil.cpu_stats()
scpustats(ctx_switches=20455687, interrupts=6598984, soft_interrupts=2134212, syscalls=0)
>>>
>>> psutil.cpu_freq()
scpufreq(current=931.42925, min=800.0, max=3500.0)
>>>
>>> psutil.getloadavg()  # also on Windows (emulated)
(3.14, 3.89, 4.67)

>>> psutil.virtual_memory()
svmem(total=10367352832, available=6472179712, percent=37.6, used=8186245120, free=2181107712, active=4748992512, inactive=2758115328, buffers=790724608, cached=3500347392, shared=787554304)
>>> psutil.swap_memory()
sswap(total=2097147904, used=296128512, free=1801019392, percent=14.1, sin=304193536, sout=677842944)
>>>

>>> psutil.disk_partitions()
[sdiskpart(device='/dev/sda1', mountpoint='/', fstype='ext4', opts='rw,nosuid', maxfile=255, maxpath=4096),
 sdiskpart(device='/dev/sda2', mountpoint='/home', fstype='ext, opts='rw', maxfile=255, maxpath=4096)]
>>>
>>> psutil.disk_usage('/')
sdiskusage(total=21378641920, used=4809781248, free=15482871808, percent=22.5)
>>>
>>> psutil.disk_io_counters(perdisk=False)
sdiskio(read_count=719566, write_count=1082197, read_bytes=18626220032, write_bytes=24081764352, read_time=5023392, write_time=63199568, read_merged_count=619166, write_merged_count=812396, busy_time=4523412)
>>>