A.1 Tutorial: The psutil Module
We can use the psutil (Python system and process utilities) module in Python scripts to retrieve information about our system configuration, running processes, and system utilization on the device.
psutil is useful mainly for system monitoring, profiling, limiting process resources, and the management of running processes. In particular,it can be used to develop new profilers and monitoring tools.
psutil implements many functionalities offered by UNIX command-line tools such as: ps, top, lsof, netstat, ifconfig, who, df, kill, free, nice, ionice, iostat, iotop, uptime, pidof, tty, taskset, pmap.
psutil currently supports Linux, Mac, and Windows systems. However, some functionalities, such as access to temperature sensor data, are limited to Linux systems. Also psutil on new architectures might provide incomplete information.
psutil provides resource information about CPU, memory, disks, processes, sensors, see this link
Links to an external site..
Below, we report some methods that can be used to retrieve information about your system (retrieved from this link) Links to an external site.
CPU
>>> 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)
Memory
>>> 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) >>>
Disk
>>> 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) >>>
Processes
>>> import psutil >>> psutil.pids() [1, 2, 3, 4, 5, 6, 7, 46, 48, 50, 51, 178, 182, 222, 223, 224, 268, 1215, 1216, 1220, 1221, 1243, 1244, 1301, 1601, 2237, 2355, 2637, 2774, 3932, 4176, 4177, 4185, 4187, 4189, 4225, 4243, 4245, 4263, 4282, 4306, 4311, 4312, 4313, 4314, 4337, 4339, 4357, 4358, 4363, 4383, 4395, 4408, 4433, 4443, 4445, 4446, 5167, 5234, 5235, 5252, 5318, 5424, 5644, 6987, 7054, 7055, 7071] >>> >>> p = psutil.Process(7055) >>> p psutil.Process(pid=7055, name='python3', status='running', started='09:04:44') >>> p.name() 'python3' >>> p.exe() '/usr/bin/python3' >>> p.cwd() '/home/giampaolo' >>> p.cmdline() ['/usr/bin/python', 'main.py'] >>> >>> p.pid 7055 >>> p.ppid() 7054 >>> p.children(recursive=True) [psutil.Process(pid=29835, name='python3', status='sleeping', started='11:45:38'), psutil.Process(pid=29836, name='python3', status='waking', started='11:43:39')] >>> >>> p.parent() psutil.Process(pid=4699, name='bash', status='sleeping', started='09:06:44') >>> p.parents() [psutil.Process(pid=4699, name='bash', started='09:06:44'), psutil.Process(pid=4689, name='gnome-terminal-server', status='sleeping', started='0:06:44'), psutil.Process(pid=1, name='systemd', status='sleeping', started='05:56:55')] >>> >>> p.status() 'running' >>> p.username() 'giampaolo' >>> p.create_time() 1267551141.5019531 >>> p.terminal() '/dev/pts/0' >>> >>> p.uids() puids(real=1000, effective=1000, saved=1000) >>> p.gids() pgids(real=1000, effective=1000, saved=1000) >>> >>> p.cpu_times() pcputimes(user=1.02, system=0.31, children_user=0.32, children_system=0.1, iowait=0.0) >>> p.cpu_percent(interval=1.0) 12.1 >>> p.cpu_affinity() [0, 1, 2, 3] >>> p.cpu_affinity([0, 1]) # set >>> p.cpu_num() 1 >>> >>> p.memory_info() pmem(rss=10915840, vms=67608576, shared=3313664, text=2310144, lib=0, data=7262208, dirty=0) >>> p.memory_full_info() # "real" USS memory usage (Linux, macOS, Win only) pfullmem(rss=10199040, vms=52133888, shared=3887104, text=2867200, lib=0, data=5967872, dirty=0, uss=6545408, pss=6872064, swap=0) >>> p.memory_percent() 0.7823 >>> p.memory_maps() [pmmap_grouped(path='/lib/x8664-linux-gnu/libutil-2.15.so', rss=32768, size=2125824, pss=32768, shared_clean=0, shared_dirty=0, private_clean=20480, private_dirty=12288, referenced=32768, anonymous=12288, swap=0), pmmap_grouped(path='/lib/x8664-linux-gnu/libc-2.15.so', rss=3821568, size=3842048, pss=3821568, shared_clean=0, shared_dirty=0, private_clean=0, private_dirty=3821568, referenced=3575808, anonymous=3821568, swap=0), pmmap_grouped(path='[heap]', rss=32768, size=139264, pss=32768, shared_clean=0, shared_dirty=0, private_clean=0, private_dirty=32768, referenced=32768, anonymous=32768, swap=0), pmmap_grouped(path='[stack]', rss=2465792, size=2494464, pss=2465792, shared_clean=0, shared_dirty=0, private_clean=0, private_dirty=2465792, referenced=2277376, anonymous=2465792, swap=0), ...] >>> >>> p.io_counters() pio(read_count=478001, write_count=59371, read_bytes=700416, write_bytes=69632, read_chars=456232, write_chars=517543) >>> >>> p.open_files() [popenfile(path='/home/giampaolo/monit.py', fd=3, position=0, mode='r', flags=32768), popenfile(path='/var/log/monit.log', fd=4, position=235542, mode='a', flags=33793)] >>> >>> p.connections(kind='tcp') [pconn(fd=115, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=addr(ip='10.0.0.1', port=48776), raddr=addr(ip='93.186.135.91', port=80), status='ESTABLISHED'), pconn(fd=117, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=addr(ip='10.0.0.1', port=43761), raddr=addr(ip='72.14.234.100', port=80), status='CLOSING')] >>> >>> p.num_threads() 4 >>> p.num_fds() 8 >>> p.threads() [pthread(id=5234, user_time=22.5, system_time=9.2891), pthread(id=5237, user_time=0.0707, system_time=1.1)] >>> >>> p.num_ctx_switches() pctxsw(voluntary=78, involuntary=19) >>> >>> p.nice() 0 >>> p.nice(10) # set >>> >>> p.ionice(psutil.IOPRIO_CLASS_IDLE) # IO priority (Win and Linux only) >>> p.ionice() pionice(ioclass=<IOPriority.IOPRIO_CLASS_IDLE: 3>, value=0) >>> >>> p.rlimit(psutil.RLIMIT_NOFILE, (5, 5)) # set resource limits (Linux only) >>> p.rlimit(psutil.RLIMIT_NOFILE) (5, 5) >>> >>> p.environ() {'LC_PAPER': 'it_IT.UTF-8', 'SHELL': '/bin/bash', 'GREP_OPTIONS': '--color=auto', 'XDG_CONFIG_DIRS': '/etc/xdg/xdg-ubuntu:/usr/share/upstart/xdg:/etc/xdg', ...} >>> >>> p.as_dict() {'status': 'running', 'num_ctx_switches': pctxsw(voluntary=63, involuntary=1), 'pid': 5457, ...} >>> p.is_running() True >>> p.suspend() >>> p.resume() >>> >>> p.terminate() >>> p.kill() >>> p.wait(timeout=3) <Exitcode.EX_OK: 0> >>> >>> psutil.test() USER PID %CPU %MEM VSZ RSS TTY START TIME COMMAND root 1 0.0 0.0 24584 2240 Jun17 00:00 init root 2 0.0 0.0 0 0 Jun17 00:00 kthreadd ... giampaolo 31475 0.0 0.0 20760 3024 /dev/pts/0 Jun19 00:00 python2.4 giampaolo 31721 0.0 2.2 773060 181896 00:04 10:30 chrome root 31763 0.0 0.0 0 0 00:05 00:00 kworker/0:1 >>>