Stdlib equivalents¶

This page maps psutil’s Python API to the closest equivalent in the Python standard library. This is useful for understanding what psutil replaces and how the two APIs differ. The most common difference is that stdlib functions only operate on the current process, while psutil works on any process (PID).

System-wide functions¶

CPU¶

psutil	stdlib	notes
`cpu_count()`	`os.cpu_count()`, `multiprocessing.cpu_count()`	Same as `cpu_count(logical=True)`; no support for physical cores (`logical=False`). See FAQ.
`cpu_count()`	`os.process_cpu_count()`	CPUs the process is allowed to use (Python 3.13+). Equivalent to `len(psutil.Process().cpu_affinity())`. See FAQ.
`getloadavg()`	`os.getloadavg()`	Same on POSIX; psutil also supports Windows.

Disk¶

psutil	stdlib	notes
`disk_usage()`	`shutil.disk_usage()`	Same as `shutil.disk_usage()`; psutil also adds `percent`. Added to CPython 3.3 (BPO-12442).
`disk_partitions()`	`os.listdrives()`, `os.listmounts()`, `os.listvolumes()`	Windows only (Python 3.12+). Low-level APIs: drive letters, volume GUIDs, mount points. psutil combines them in one cross-platform call.

Network¶

psutil	stdlib	notes
`net_if_addrs()`	`socket.if_nameindex()`	Stdlib returns NIC names only; psutil also returns addresses, netmasks, broadcast, and PTP.

Process¶

psutil	stdlib	notes
`pid_exists()`	`os.kill(pid, 0)`	Common POSIX idiom; psutil also supports Windows.

Process methods¶

Assuming p = psutil.Process().

Identity¶

psutil	stdlib	notes
`p.pid`	`os.getpid()`
`p.ppid()`	`os.getppid()`
`p.cwd()`	`os.getcwd()`
`p.environ()`	`os.environ`	Will differ from launch environment if modified at runtime.
`p.exe()`	`sys.executable`	Python interpreter path only.
`p.cmdline()`	`sys.argv`	Python process only.

Credentials¶

psutil	stdlib	notes
`p.uids()`	`os.getuid()`, `os.geteuid()`, `os.getresuid()`
`p.gids()`	`os.getgid()`, `os.getegid()`, `os.getresgid()`
`p.username()`	`os.getlogin()`, `getpass.getuser()`	Rough equivalent; not per-process.

CPU / scheduling¶

psutil	stdlib	notes
`p.cpu_times()`	`os.times()`	`os.times()` also has `elapsed`; psutil adds `iowait` (Linux).
`p.cpu_times()`	`resource.getrusage()`	`ru_utime` / `ru_stime` match; have higher precision.
`p.num_ctx_switches()`	`resource.getrusage()`	Current process only; psutil works for any PID.
`p.nice()`	`os.getpriority()`, `os.setpriority()`	POSIX only; psutil also supports Windows. Added to CPython 3.3 (BPO-10784).
`p.nice()`	`os.nice()`	POSIX only; psutil also supports Windows.
no equivalent	`os.sched_getscheduler()`, `os.sched_setscheduler()`	Sets scheduling policy (`SCHED_*`). Unlike nice, which sets priority within `SCHED_OTHER`. Real-time policies preempt normal processes.
`p.cpu_affinity()`	`os.sched_getaffinity()`, `os.sched_setaffinity()`	Nearly equivalent; both accept a PID. Stdlib is Linux/BSD; psutil also supports Windows.
`p.rlimit()`	`resource.getrlimit()`, `resource.setrlimit()`	Same interface; psutil works for any PID (Linux only).

Memory¶

psutil	stdlib	notes
`p.memory_info()`	`resource.getrusage()`	Only peak_rss (`ru_maxrss`); psutil returns RSS, VMS, and more.
`p.page_faults()`	`resource.getrusage()`	Current process only.

I/O¶

psutil	stdlib	notes
`p.io_counters()`	`resource.getrusage()`	Block I/O only (`ru_inblock` / `ru_oublock`), current process. psutil returns bytes and counts for any PID.

Threads¶

psutil	stdlib	notes
`p.num_threads()`	`threading.active_count()`	Stdlib counts Python threads only; psutil counts all OS threads.
`p.threads()`	`threading.enumerate()`	Stdlib returns `threading.Thread` objects; psutil returns OS thread IDs with CPU times.

Signals¶

psutil	stdlib	notes
`p.send_signal()`	`os.kill()`	Same on POSIX; limited on Windows. psutil adds `NoSuchProcess` / `AccessDenied` and avoids killing reused PIDs.
`p.suspend()`	`os.kill()` + `signal.SIGSTOP`	Same as above.
`p.resume()`	`os.kill()` + `signal.SIGCONT`	Same as above.
`p.terminate()`	`os.kill()` + `signal.SIGTERM`	Same as above. On Windows uses `TerminateProcess()`.
`p.kill()`	`os.kill()` + `signal.SIGKILL`	Same as above. On Windows uses `TerminateProcess()`.
`p.wait()`	`os.waitpid()`	Child processes only; psutil works for any PID.
`p.wait()`	`subprocess.Popen.wait()`	Equivalent; psutil uses efficient OS-level waiting on Linux/BSD. Added to CPython 3.15 (cpython/PR-144047).