Python3.6 psutil官方开发文档

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## psutil documentation[¶][Link 1] ##

### Quick links ###

*  [Home page][]
 *  [Install][]
 *  [Blog][]
 *  [Forum][]
 *  [Download][]
 *  [Development guide][]
 *  [What’s new][What_s new]

### About ###

psutil (python system and process utilities) is a cross-platform library for retrieving information on running **processes** and **system utilization** (CPU, memory, disks, network) in **Python**. It is useful mainly for **system monitoring**, **profiling** and **limiting process resources** and **management of running processes**. It implements many functionalities offered by command line tools such as: *ps, top, lsof, netstat, ifconfig, who, df, kill, free, nice, ionice, iostat, iotop, uptime, pidof, tty, taskset, pmap*. It currently supports **Linux, Windows, OSX, Sun Solaris, FreeBSD, OpenBSD** and **NetBSD**, both **32-bit** and **64-bit** architectures, with Python versions from **2.6 to 3.5** (users of Python 2.4 and 2.5 may use [2.1.3][] version). [PyPy][] is also known to work.

The psutil documentation you’re reading is distributed as a single HTML page.

## System related functions ##

### CPU ###

`psutil.` `cpu_times` (*percpu=False*)

Return system CPU times as a namedtuple. Every attribute represents the seconds the CPU has spent in the given mode. The attributes availability varies depending on the platform:

*  **user**
 *  **system**
 *  **idle**

Platform-specific fields:

*  **nice** *(UNIX)*
 *  **iowait** *(Linux)*
 *  **irq** *(Linux, BSD)*
 *  **softirq** *(Linux)*
 *  **steal** *(Linux 2.6.11+)*
 *  **guest** *(Linux 2.6.24+)*
 *  **guest\_nice** *(Linux 3.2.0+)*
 *  **interrupt** *(Windows)*
 *  **dpc** *(Windows)*

When *percpu* is `True` return a list of namedtuples for each logical CPU on the system. First element of the list refers to first CPU, second element to second CPU and so on. The order of the list is consistent across calls. Example output on Linux:

>>> import psutil
    >>> psutil.cpu_times() scputimes(user=17411.7, nice=77.99, system=3797.02, idle=51266.57, iowait=732.58, irq=0.01, softirq=142.43, steal=0.0, guest=0.0, guest_nice=0.0)

Changed in version 4.1.0: added *interrupt* and *dpc* fields on Windows.

`psutil.` `cpu_percent` (*interval=None*, *percpu=False*)

Return a float representing the current system-wide CPU utilization as a percentage. When *interval* is > `0.0` compares system CPU times elapsed before and after the interval (blocking). When *interval* is `0.0` or `None` compares system CPU times elapsed since last call or module import, returning immediately. That means the first time this is called it will return a meaningless `0.0` value which you are supposed to ignore. In this case is recommended for accuracy that this function be called with at least `0.1` seconds between calls. When *percpu* is `True` returns a list of floats representing the utilization as a percentage for each CPU. First element of the list refers to first CPU, second element to second CPU and so on. The order of the list is consistent across calls.

>>> import psutil
    >>> # blocking
    >>> psutil.cpu_percent(interval=1) 2.0 >>> # non-blocking (percentage since last call) >>> psutil.cpu_percent(interval=None) 2.9 >>> # blocking, per-cpu >>> psutil.cpu_percent(interval=1, percpu=True) [2.0, 1.0] >>>

Warning

the first time this function is called with *interval* = `0.0` or `None` it will return a meaningless `0.0` value which you are supposed to ignore.

`psutil.` `cpu_times_percent` (*interval=None*, *percpu=False*)

Same as [`cpu_percent()`][cpu_percent] but provides utilization percentages for each specific CPU time as is returned by [`psutil.cpu_times(percpu=True)`][psutil.cpu_times_percpu_True]. *interval* and*percpu* arguments have the same meaning as in [`cpu_percent()`][cpu_percent].

Warning

the first time this function is called with *interval* = `0.0` or `None` it will return a meaningless `0.0` value which you are supposed to ignore.

Changed in version 4.1.0: two new *interrupt* and *dpc* fields are returned on Windows.

`psutil.` `cpu_count` (*logical=True*)

Return the number of logical CPUs in the system (same as [os.cpu\_count()][os.cpu_count] in Python 3.4). If *logical* is `False` return the number of physical cores only (hyper thread CPUs are excluded). Return `None` if undetermined.

>>> import psutil
    >>> psutil.cpu_count() 4 >>> psutil.cpu_count(logical=False) 2 >>>

`psutil.` `cpu_stats` ()

Return various CPU statistics as a namedtuple:

*  **ctx\_switches**: number of context switches (voluntary + involuntary) since boot.
 *  **interrupts**: number of interrupts since boot.
 *  **soft\_interrupts**: number of software interrupts since boot. Always set to `0` on Windows and SunOS.
 *  **syscalls**: number of system calls since boot. Always set to `0` on Linux.

Example (Linux):

>>> import psutil
    >>> psutil.cpu_stats() scpustats(ctx_switches=20455687, interrupts=6598984, soft_interrupts=2134212, syscalls=0)

New in version 4.1.0.

### Memory ###

`psutil.` `virtual_memory` ()

Return statistics about system memory usage as a namedtuple including the following fields, expressed in bytes:

*  **total**: total physical memory available.
 *  **available**: the actual amount of available memory that can be given instantly to processes that request more memory in bytes; this is calculated by summing different memory values depending on the platform (e.g. free + buffers + cached on Linux) and it is supposed to be used to monitor actual memory usage in a cross platform fashion.
 *  **percent**: the percentage usage calculated as `(total - available) / total * 100`.
 *  **used**: memory used, calculated differently depending on the platform and designed for informational purposes only.
 *  **free**: memory not being used at all (zeroed) that is readily available; note that this doesn’t reflect the actual memory available (use ‘available’ instead).

Platform-specific fields:

*  **active** *(UNIX)*: memory currently in use or very recently used, and so it is in RAM.
 *  **inactive** *(UNIX)*: memory that is marked as not used.
 *  **buffers** *(Linux, BSD)*: cache for things like file system metadata.
 *  **cached** *(Linux, BSD)*: cache for various things.
 *  **shared** *(Linux, BSD)*: memory that may be simultaneously accessed by multiple processes.
 *  **wired** *(BSD, OSX)*: memory that is marked to always stay in RAM. It is never moved to disk.

The sum of **used** and **available** does not necessarily equal **total**. On Windows **available** and **free** are the same. See [scripts/meminfo.py][scripts_meminfo.py] script providing an example on how to convert bytes in a human readable form.

Note

if you just want to know how much physical memory is left in a cross platform fashion simply rely on the **available** field.

>>> import psutil
    >>> mem = psutil.virtual_memory() >>> mem svmem(total=10367352832, available=6472179712, percent=37.6, used=8186245120, free=2181107712, active=4748992512, inactive=2758115328, buffers=790724608, cached=3500347392, shared=787554304) >>> >>> THRESHOLD = 100 * 1024 * 1024 # 100MB >>> if mem.available <= THRESHOLD: ... print("warning") ... >>>

Changed in version 4.2.0: added *shared* metrics on Linux.

`psutil.` `swap_memory` ()

Return system swap memory statistics as a namedtuple including the following fields:

*  **total**: total swap memory in bytes
 *  **used**: used swap memory in bytes
 *  **free**: free swap memory in bytes
 *  **percent**: the percentage usage calculated as `(total - available) / total * 100`
 *  **sin**: the number of bytes the system has swapped in from disk (cumulative)
 *  **sout**: the number of bytes the system has swapped out from disk (cumulative)

**sin** and **sout** on Windows are always set to `0`. See [scripts/meminfo.py][scripts_meminfo.py] script providing an example on how to convert bytes in a human readable form.

>>> import psutil
    >>> psutil.swap_memory() sswap(total=2097147904L, used=886620160L, free=1210527744L, percent=42.3, sin=1050411008, sout=1906720768)

### Disks ###

`psutil.` `disk_partitions` (*all=False*)

Return all mounted disk partitions as a list of namedtuples including device, mount point and filesystem type, similarly to “df” command on UNIX. If *all*parameter is `False` return physical devices only (e.g. hard disks, cd-rom drives, USB keys) and ignore all others (e.g. memory partitions such as[/dev/shm][dev_shm]). Namedtuple’s **fstype** field is a string which varies depending on the platform. On Linux it can be one of the values found in /proc/filesystems (e.g. `'ext3'` for an ext3 hard drive o `'iso9660'` for the CD-ROM drive). On Windows it is determined via [GetDriveType][] and can be either `"removable"`, `"fixed"`,`"remote"`, `"cdrom"`, `"unmounted"` or `"ramdisk"`. On OSX and BSD it is retrieved via [getfsstat(2)][getfsstat_2]. See [disk\_usage.py][disk_usage.py] script providing an example usage.

>>> import psutil
    >>> psutil.disk_partitions() [sdiskpart(device='/dev/sda3', mountpoint='/', fstype='ext4', opts='rw,errors=remount-ro'), sdiskpart(device='/dev/sda7', mountpoint='/home', fstype='ext4', opts='rw')]

`psutil.` `disk_usage` (*path*)

Return disk usage statistics about the given *path* as a namedtuple including **total**, **used** and **free** space expressed in bytes, plus the **percentage**usage. [OSError][] is raised if *path* does not exist. Starting from [Python 3.3][] this is also available as [shutil.disk\_usage()][shutil.disk_usage]. See [disk\_usage.py][disk_usage.py] script providing an example usage.

>>> import psutil
    >>> psutil.disk_usage('/') sdiskusage(total=21378641920, used=4809781248, free=15482871808, percent=22.5)

Note

UNIX usually reserves 5% of the total disk space for the root user. *total* and *used* fields on UNIX refer to the overall total and used space, whereas *free* represents the space available for the **user** and *percent* represents the **user** utilization (see [source code][]). That is why *percent* value may look 5% bigger than what you would expect it to be. Also note that both 4 values match “df” cmdline utility.

Changed in version 4.3.0: *percent* value takes root reserved space into account.

`psutil.` `disk_io_counters` (*perdisk=False*)

Return system-wide disk I/O statistics as a namedtuple including the following fields:

*  **read\_count**: number of reads
 *  **write\_count**: number of writes
 *  **read\_bytes**: number of bytes read
 *  **write\_bytes**: number of bytes written

Platform-specific fields:

*  **read\_time**: (all except *NetBSD* and *OpenBSD*) time spent reading from disk (in milliseconds)
 *  **write\_time**: (all except *NetBSD* and *OpenBSD*) time spent writing to disk (in milliseconds)
 *  **busy\_time**: (*Linux*, *FreeBSD*) time spent doing actual I/Os (in milliseconds)
 *  **read\_merged\_count** (*Linux*): number of merged reads (see [iostat doc][])
 *  **write\_merged\_count** (*Linux*): number of merged writes (see [iostats doc][iostat doc])

If *perdisk* is `True` return the same information for every physical disk installed on the system as a dictionary with partition names as the keys and the namedtuple described above as the values. See [scripts/iotop.py][scripts_iotop.py] for an example application.

>>> import psutil
    >>> psutil.disk_io_counters() sdiskio(read_count=8141, write_count=2431, read_bytes=290203, write_bytes=537676, read_time=5868, write_time=94922) >>> >>> psutil.disk_io_counters(perdisk=True) {'sda1': sdiskio(read_count=920, write_count=1, read_bytes=2933248, write_bytes=512, read_time=6016, write_time=4), 'sda2': sdiskio(read_count=18707, write_count=8830, read_bytes=6060, write_bytes=3443, read_time=24585, write_time=1572), 'sdb1': sdiskio(read_count=161, write_count=0, read_bytes=786432, write_bytes=0, read_time=44, write_time=0)}

Warning

on some systems such as Linux, on a very busy or long-lived system these numbers may wrap (restart from zero), see [issues \#802][issues _802]. Applications should be prepared to deal with that.

Changed in version 4.0.0: added *busy\_time* (Linux, FreeBSD), *read\_merged\_count* and *write\_merged\_count* (Linux) fields.

Changed in version 4.0.0: NetBSD no longer has *read\_time* and *write\_time* fields.

### Network ###

`psutil.` `net_io_counters` (*pernic=False*)

Return system-wide network I/O statistics as a namedtuple including the following attributes:

*  **bytes\_sent**: number of bytes sent
 *  **bytes\_recv**: number of bytes received
 *  **packets\_sent**: number of packets sent
 *  **packets\_recv**: number of packets received
 *  **errin**: total number of errors while receiving
 *  **errout**: total number of errors while sending
 *  **dropin**: total number of incoming packets which were dropped
 *  **dropout**: total number of outgoing packets which were dropped (always 0 on OSX and BSD)

If *pernic* is `True` return the same information for every network interface installed on the system as a dictionary with network interface names as the keys and the namedtuple described above as the values. See [scripts/nettop.py][scripts_nettop.py] for an example application.

>>> import psutil
    >>> psutil.net_io_counters() snetio(bytes_sent=14508483, bytes_recv=62749361, packets_sent=84311, packets_recv=94888, errin=0, errout=0, dropin=0, dropout=0) >>> >>> psutil.net_io_counters(pernic=True) {'lo': snetio(bytes_sent=547971, bytes_recv=547971, packets_sent=5075, packets_recv=5075, errin=0, errout=0, dropin=0, dropout=0), 'wlan0': snetio(bytes_sent=13921765, bytes_recv=62162574, packets_sent=79097, packets_recv=89648, errin=0, errout=0, dropin=0, dropout=0)}

Warning

on some systems such as Linux, on a very busy or long-lived system these numbers may wrap (restart from zero), see [issues \#802][issues _802]. Applications should be prepared to deal with that.

`psutil.` `net_connections` (*kind='inet'*)

Return system-wide socket connections as a list of namedtuples. Every namedtuple provides 7 attributes:

*  **fd**: the socket file descriptor, if retrievable, else `-1`. If the connection refers to the current process this may be passed to [socket.fromfd()][socket.fromfd] to obtain a usable socket object.
 *  **family**: the address family, either [AF\_INET][AF_INET], [AF\_INET6][AF_INET6] or [AF\_UNIX][AF_UNIX].
 *  **type**: the address type, either [SOCK\_STREAM][SOCK_STREAM] or [SOCK\_DGRAM][SOCK_DGRAM].
 *  **laddr**: the local address as a `(ip, port)` tuple or a `path` in case of AF\_UNIX sockets.
 *  **raddr**: the remote address as a `(ip, port)` tuple or an absolute `path` in case of UNIX sockets. When the remote endpoint is not connected you’ll get an empty tuple (AF\_INET\*) or `None` (AF\_UNIX). On Linux AF\_UNIX sockets will always have this set to `None`.
 *  **status**: represents the status of a TCP connection. The return value is one of the [`psutil.CONN_*`][psutil.CONN] constants (a string). For UDP and UNIX sockets this is always going to be [`psutil.CONN_NONE`][psutil.CONN_NONE].
 *  **pid**: the PID of the process which opened the socket, if retrievable, else `None`. On some platforms (e.g. Linux) the availability of this field changes depending on process privileges (root is needed).

The *kind* parameter is a string which filters for connections that fit the following criteria:

On OSX this function requires root privileges. To get per-process connections use [`Process.connections()`][Process.connections]. Also, see [netstat.py sample script][]. Example:

>>> import psutil
    >>> psutil.net_connections() [pconn(fd=115, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 48776), raddr=('93.186.135.91', 80), status='ESTABLISHED', pid=1254), pconn(fd=117, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 43761), raddr=('72.14.234.100', 80), status='CLOSING', pid=2987), pconn(fd=-1, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 60759), raddr=('72.14.234.104', 80), status='ESTABLISHED', pid=None), pconn(fd=-1, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 51314), raddr=('72.14.234.83', 443), status='SYN_SENT', pid=None) ...]

Note

(OSX) [`psutil.AccessDenied`][psutil.AccessDenied] is always raised unless running as root (lsof does the same).

Note

(Solaris) UNIX sockets are not supported.

New in version 2.1.0.

`psutil.` `net_if_addrs` ()

Return the addresses associated to each NIC (network interface card) installed on the system as a dictionary whose keys are the NIC names and value is a list of namedtuples for each address assigned to the NIC. Each namedtuple includes 5 fields:

*  **family**
 *  **address**
 *  **netmask**
 *  **broadcast**
 *  **ptp**

*family* can be either [AF\_INET][AF_INET], [AF\_INET6][AF_INET6] or [`psutil.AF_LINK`][psutil.AF_LINK], which refers to a MAC address. *address* is the primary address and it is always set.*netmask*, *broadcast* and *ptp* may be `None`. *ptp* stands for “point to point” and references the destination address on a point to point interface (tipically a VPN). *broadcast* and *ptp* are mutually exclusive. *netmask*, *broadcast* and *ptp* are not supported on Windows and are set to `None`.

Example:

>>> import psutil
    >>> psutil.net_if_addrs() {'lo': [snic(family=<AddressFamily.AF_INET: 2>, address='127.0.0.1', netmask='255.0.0.0', broadcast='127.0.0.1', ptp=None), snic(family=<AddressFamily.AF_INET6: 10>, address='::1', netmask='ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff', broadcast=None, ptp=None), snic(family=<AddressFamily.AF_LINK: 17>, address='00:00:00:00:00:00', netmask=None, broadcast='00:00:00:00:00:00', ptp=None)], 'wlan0': [snic(family=<AddressFamily.AF_INET: 2>, address='192.168.1.3', netmask='255.255.255.0', broadcast='192.168.1.255', ptp=None), snic(family=<AddressFamily.AF_INET6: 10>, address='fe80::c685:8ff:fe45:641%wlan0', netmask='ffff:ffff:ffff:ffff::', broadcast=None, ptp=None), snic(family=<AddressFamily.AF_LINK: 17>, address='c4:85:08:45:06:41', netmask=None, broadcast='ff:ff:ff:ff:ff:ff', ptp=None)]} >>>

See also [scripts/ifconfig.py][scripts_ifconfig.py] for an example application.

Note

if you’re interested in others families (e.g. AF\_BLUETOOTH) you can use the more powerful [netifaces][] extension.

Note

you can have more than one address of the same family associated with each interface (that’s why dict values are lists).

Note

*netmask*, *broadcast* and *ptp* are not supported on Windows and are set to `None`.

New in version 3.0.0.

Changed in version 3.2.0: *ptp* field was added.

`psutil.` `net_if_stats` ()

Return information about each NIC (network interface card) installed on the system as a dictionary whose keys are the NIC names and value is a namedtuple with the following fields:

*  **isup**: a bool indicating whether the NIC is up and running.
 *  **duplex**: the duplex communication type; it can be either [`NIC_DUPLEX_FULL`][NIC_DUPLEX_FULL], [`NIC_DUPLEX_HALF`][NIC_DUPLEX_HALF] or [`NIC_DUPLEX_UNKNOWN`][NIC_DUPLEX_UNKNOWN].
 *  **speed**: the NIC speed expressed in mega bits (MB), if it can’t be determined (e.g. ‘localhost’) it will be set to `0`.
 *  **mtu**: NIC’s maximum transmission unit expressed in bytes.

See also [scripts/ifconfig.py][scripts_ifconfig.py] for an example application. Example:

>>> import psutil
    >>> psutil.net_if_stats() {'eth0': snicstats(isup=True, duplex=<NicDuplex.NIC_DUPLEX_FULL: 2>, speed=100, mtu=1500), 'lo': snicstats(isup=True, duplex=<NicDuplex.NIC_DUPLEX_UNKNOWN: 0>, speed=0, mtu=65536)}

New in version 3.0.0.

### Other system info ###

`psutil.` `boot_time` ()

Return the system boot time expressed in seconds since the epoch. Example:

>>> import psutil, datetime
    >>> psutil.boot_time() 1389563460.0 >>> datetime.datetime.fromtimestamp(psutil.boot_time()).strftime("%Y-%m-%d %H:%M:%S") '2014-01-12 22:51:00'

`psutil.` `users` ()

Return users currently connected on the system as a list of namedtuples including the following fields:

*  **user**: the name of the user.
 *  **terminal**: the tty or pseudo-tty associated with the user, if any, else `None`.
 *  **host**: the host name associated with the entry, if any.
 *  **started**: the creation time as a floating point number expressed in seconds since the epoch.

Example:

>>> import psutil
    >>> psutil.users() [suser(name='giampaolo', terminal='pts/2', host='localhost', started=1340737536.0), suser(name='giampaolo', terminal='pts/3', host='localhost', started=1340737792.0)]

## Processes ##

### Functions ###

`psutil.` `pids` ()

Return a list of current running PIDs. To iterate over all processes [`process_iter()`][process_iter] should be preferred.

`psutil.` `pid_exists` (*pid*)

Check whether the given PID exists in the current process list. This is faster than doing `"pid in psutil.pids()"` and should be preferred.

`psutil.` `process_iter` ()

Return an iterator yielding a [`Process`][Process] class instance for all running processes on the local machine. Every instance is only created once and then cached into an internal table which is updated every time an element is yielded. Cached [`Process`][Process] instances are checked for identity so that you’re safe in case a PID has been reused by another process, in which case the cached instance is updated. This is should be preferred over [`psutil.pids()`][psutil.pids] for iterating over processes. Sorting order in which processes are returned is based on their PID. Example usage:

import psutil
    
    for proc in psutil.process_iter(): try: pinfo = proc.as_dict(attrs=['pid', 'name']) except psutil.NoSuchProcess: pass else: print(pinfo)

`psutil.` `wait_procs` (*procs*, *timeout=None*, *callback=None*)

Convenience function which waits for a list of [`Process`][Process] instances to terminate. Return a `(gone, alive)` tuple indicating which processes are gone and which ones are still alive. The *gone* ones will have a new *returncode* attribute indicating process exit status (it may be `None`). `callback` is a function which gets called every time a process terminates (a [`Process`][Process] instance is passed as callback argument). Function will return as soon as all processes terminate or when timeout occurs. Tipical use case is:

*  send SIGTERM to a list of processes
 *  give them some time to terminate
 *  send SIGKILL to those ones which are still alive

Example:

import psutil
    
    def on_terminate(proc): print("process {} terminated with exit code {}".format(proc, proc.returncode)) procs = [...] # a list of Process instances for p in procs: p.terminate() gone, alive = wait_procs(procs, timeout=3, callback=on_terminate) for p in alive: p.kill()

### Exceptions ###

*class*  `psutil.` `Error`

Base exception class. All other exceptions inherit from this one.

*class*  `psutil.` `NoSuchProcess` (*pid*, *name=None*, *msg=None*)

Raised by [`Process`][Process] class methods when no process with the given pid\* is found in the current process list or when a process no longer exists. “name” is the name the process had before disappearing and gets set only if [`Process.name()`][Process.name] was previosly called.

*class*  `psutil.` `ZombieProcess` (*pid*, *name=None*, *ppid=None*, *msg=None*)

This may be raised by [`Process`][Process] class methods when querying a zombie process on UNIX (Windows doesn’t have zombie processes). Depending on the method called the OS may be able to succeed in retrieving the process information or not. Note: this is a subclass of [`NoSuchProcess`][NoSuchProcess] so if you’re not interested in retrieving zombies (e.g. when using [`process_iter()`][process_iter]) you can ignore this exception and just catch [`NoSuchProcess`][NoSuchProcess].

New in version 3.0.0.

*class*  `psutil.` `AccessDenied` (*pid=None*, *name=None*, *msg=None*)

Raised by [`Process`][Process] class methods when permission to perform an action is denied. “name” is the name of the process (may be `None`).

*class*  `psutil.` `TimeoutExpired` (*seconds*, *pid=None*, *name=None*, *msg=None*)

Raised by [`Process.wait()`][Process.wait] if timeout expires and process is still alive.

### Process class ###

*class*  `psutil.` `Process` (*pid=None*)

Represents an OS process with the given *pid*. If *pid* is omitted current process *pid* ([os.getpid()][os.getpid]) is used. Raise [`NoSuchProcess`][NoSuchProcess] if *pid* does not exist. When accessing methods of this class always be prepared to catch [`NoSuchProcess`][NoSuchProcess], [`ZombieProcess`][ZombieProcess] and [`AccessDenied`][psutil.AccessDenied] exceptions. [hash()][hash] builtin can be used against instances of this class in order to identify a process univocally over time (the hash is determined by mixing process PID and creation time). As such it can also be used with [set()s][set_s].

Warning

the way this class is bound to a process is via its **PID**. That means that if the [`Process`][Process] instance is old enough and the PID has been reused in the meantime you might end up interacting with another process. The only exceptions for which process identity is preemptively checked (via PID + creation time) and guaranteed are for [`nice()`][nice] (set), [`ionice()`][ionice] (set), [`cpu_affinity()`][cpu_affinity] (set), [`rlimit()`][rlimit] (set), [`children()`][children], [`parent()`][parent], [`suspend()`][suspend] [`resume()`][resume],[`send_signal()`][send_signal], [`terminate()`][terminate], and [`kill()`][kill] methods. To prevent this problem for all other methods you can use [`is_running()`][is_running] before querying the process or use [`process_iter()`][process_iter] in case you’re iterating over all processes.

`pid`

The process PID.

`ppid` ()

The process parent pid. On Windows the return value is cached after first call.

`name` ()

The process name.

`exe` ()

The process executable as an absolute path. On some systems this may also be an empty string. The return value is cached after first call.

`cmdline` ()

The command line this process has been called with.

`environ` ()

The environment variables of the process as a dict. Note: this might not reflect changes made after the process started.

Availability: Linux, OSX, Windows

New in version 4.0.0.

`create_time` ()

The process creation time as a floating point number expressed in seconds since the epoch, in [UTC][]. The return value is cached after first call.

>>> import psutil, datetime
    >>> p = psutil.Process() >>> p.create_time() 1307289803.47 >>> datetime.datetime.fromtimestamp(p.create_time()).strftime("%Y-%m-%d %H:%M:%S") '2011-03-05 18:03:52'

`as_dict` (*attrs=None*, *ad\_value=None*)

Utility method retrieving multiple process information as a dictionary. If *attrs* is specified it must be a list of strings reflecting available [`Process`][Process]class’s attribute names (e.g. `['cpu_times', 'name']`), else all public (read only) attributes are assumed. *ad\_value* is the value which gets assigned to a dict key in case [`AccessDenied`][psutil.AccessDenied] or [`ZombieProcess`][ZombieProcess] exception is raised when retrieving that particular process information.

>>> import psutil
    >>> p = psutil.Process() >>> p.as_dict(attrs=['pid', 'name', 'username']) {'username': 'giampaolo', 'pid': 12366, 'name': 'python'}

Changed in version 3.0.0: *ad\_value* is used also when incurring into [`ZombieProcess`][ZombieProcess] exception, not only [`AccessDenied`][psutil.AccessDenied]

`parent` ()

Utility method which returns the parent process as a [`Process`][Process] object preemptively checking whether PID has been reused. If no parent PID is known return `None`.

`status` ()

The current process status as a string. The returned string is one of the [`psutil.STATUS_*`][psutil.STATUS] constants.

`cwd` ()

The process current working directory as an absolute path.

`username` ()

The name of the user that owns the process. On UNIX this is calculated by using real process uid.

`uids` ()

The real, effective and saved user ids of this process as a namedtuple. This is the same as [os.getresuid()][os.getresuid] but can be used for any process PID.

Availability: UNIX

`gids` ()

The real, effective and saved group ids of this process as a namedtuple. This is the same as [os.getresgid()][os.getresgid] but can be used for any process PID.

Availability: UNIX

`terminal` ()

The terminal associated with this process, if any, else `None`. This is similar to “tty” command but can be used for any process PID.

Availability: UNIX

`nice` (*value=None*)

Get or set process [niceness][] (priority). On UNIX this is a number which usually goes from `-20` to `20`. The higher the nice value, the lower the priority of the process.

>>> import psutil
    >>> p = psutil.Process() >>> p.nice(10) # set >>> p.nice() # get 10 >>>

Starting from [Python 3.3][Python 3.3 1] this functionality is also available as [os.getpriority()][os.getpriority] and [os.setpriority()][os.setpriority] (UNIX only). On Windows this is implemented via[GetPriorityClass][] and [SetPriorityClass][] Windows APIs and *value* is one of the [`psutil.*_PRIORITY_CLASS`][psutil._PRIORITY_CLASS] constants reflecting the MSDN documentation. Example which increases process priority on Windows:

>>> p.nice(psutil.HIGH_PRIORITY_CLASS)

`ionice` (*ioclass=None*, *value=None*)

Get or set [process I/O niceness][process I_O niceness] (priority). On Linux *ioclass* is one of the [`psutil.IOPRIO_CLASS_*`][psutil.IOPRIO_CLASS] constants. *value* is a number which goes from `0` to `7`. The higher the value, the lower the I/O priority of the process. On Windows only *ioclass* is used and it can be set to `2` (normal), `1` (low) or `0` (very low). The example below sets IDLE priority class for the current process, meaning it will only get I/O time when no other process needs the disk:

>>> import psutil
    >>> p = psutil.Process() >>> p.ionice(psutil.IOPRIO_CLASS_IDLE) # set >>> p.ionice() # get pionice(ioclass=<IOPriority.IOPRIO_CLASS_IDLE: 3>, value=0) >>>

On Windows only *ioclass* is used and it can be set to `2` (normal), `1` (low) or `0` (very low).

Availability: Linux and Windows > Vista

Changed in version 3.0.0: on Python >= 3.4 the returned `ioclass` constant is an [enum][] instead of a plain integer.

`rlimit` (*resource*, *limits=None*)

Get or set process resource limits (see [man prlimit][]). *resource* is one of the [`psutil.RLIMIT_*`][psutil.RLIMIT] constants. *limits* is a `(soft, hard)` tuple. This is the same as [resource.getrlimit()][resource.getrlimit] and [resource.setrlimit()][resource.setrlimit] but can be used for any process PID, not only [os.getpid()][os.getpid]. Example:

>>> import psutil
    >>> p = psutil.Process() >>> # process may open no more than 128 file descriptors >>> p.rlimit(psutil.RLIMIT_NOFILE, (128, 128)) >>> # process may create files no bigger than 1024 bytes >>> p.rlimit(psutil.RLIMIT_FSIZE, (1024, 1024)) >>> # get >>> p.rlimit(psutil.RLIMIT_FSIZE) (1024, 1024) >>>

Availability: Linux

`io_counters` ()

Return process I/O statistics as a namedtuple including the number of read and write operations performed by the process and the amount of bytes read and written. For Linux refer to [/proc filesysem documentation][proc filesysem documentation]. On BSD there’s apparently no way to retrieve bytes counters, hence `-1` is returned for **read\_bytes** and **write\_bytes** fields. OSX is not supported.

>>> import psutil
    >>> p = psutil.Process() >>> p.io_counters() pio(read_count=454556, write_count=3456, read_bytes=110592, write_bytes=0)

Availability: all platforms except OSX and Solaris

`num_ctx_switches` ()

The number voluntary and involuntary context switches performed by this process.

`num_fds` ()

The number of file descriptors used by this process.

Availability: UNIX

`num_handles` ()

The number of handles used by this process.

Availability: Windows

`num_threads` ()

The number of threads used by this process.

`threads` ()

Return threads opened by process as a list of namedtuples including thread id and thread CPU times (user/system). On OpenBSD this method requires root access.

`cpu_times` ()

Return a (user, system, children\_user, children\_system) namedtuple representing the accumulated process time, in seconds (see [explanation][]). On Windows and OSX only *user* and *system* are filled, the others are set to `0`. This is similar to [os.times()][os.times] but can be used for any process PID.

Changed in version 4.1.0: return two extra fields: *children\_user* and *children\_system*.

`cpu_percent` (*interval=None*)

Return a float representing the process CPU utilization as a percentage. The returned value refers to the utilization of a single CPU, i.e. it is not evenly split between the number of available CPU cores. When *interval* is > `0.0` compares process times to system CPU times elapsed before and after the interval (blocking). When interval is `0.0` or `None` compares process times to system CPU times elapsed since last call, returning immediately. That means the first time this is called it will return a meaningless `0.0` value which you are supposed to ignore. In this case is recommended for accuracy that this function be called a second time with at least `0.1` seconds between calls. Example:

>>> import psutil
    >>> p = psutil.Process() >>> >>> # blocking >>> p.cpu_percent(interval=1) 2.0 >>> # non-blocking (percentage since last call) >>> p.cpu_percent(interval=None) 2.9 >>>

Note

a percentage > 100 is legitimate as it can result from a process with multiple threads running on different CPU cores.

Note

the returned value is explcitly **not** split evenly between all CPUs cores (differently from [`psutil.cpu_percent()`][cpu_percent]). This means that a busy loop process running on a system with 2 CPU cores will be reported as having 100% CPU utilization instead of 50%. This was done in order to be consistent with UNIX’s “top” utility and also to make it easier to identify processes hogging CPU resources (independently from the number of CPU cores). It must be noted that in the example above taskmgr.exe on Windows will report 50% usage instead. To emulate Windows’s taskmgr.exe behavior you can do: `p.cpu_percent() / psutil.cpu_count()`.

Warning

the first time this method is called with interval = `0.0` or `None` it will return a meaningless `0.0` value which you are supposed to ignore.

`cpu_affinity` (*cpus=None*)

Get or set process current [CPU affinity][]. CPU affinity consists in telling the OS to run a certain process on a limited set of CPUs only. The number of eligible CPUs can be obtained with `list(range(psutil.cpu_count()))`. `ValueError` will be raise on set in case an invalid CPU number is specified.

>>> import psutil
    >>> psutil.cpu_count() 4 >>> p = psutil.Process() >>> p.cpu_affinity() # get [0, 1, 2, 3] >>> p.cpu_affinity([0]) # set; from now on, process will run on CPU #0 only >>> p.cpu_affinity() [0] >>> >>> # reset affinity against all CPUs >>> all_cpus = list(range(psutil.cpu_count())) >>> p.cpu_affinity(all_cpus) >>>

Availability: Linux, Windows, FreeBSD

Changed in version 2.2.0: added support for FreeBSD

`memory_info` ()

Return a namedtuple with variable fields depending on the platform representing memory information about the process. The “portable” fields available on all plaforms are rss and vms. All numbers are expressed in bytes.

<table style="border:1px solid silver; border-collapse:collapse; word-break:break-word">        
 <thead> 
  <tr> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> Linux</th> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> OSX</th> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> BSD</th> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> Solaris</th> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> Windows</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss (alias for&nbsp;<code>wset</code>)</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> vms</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> vms</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> vms</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> vms</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> vms (alias for&nbsp;<code>pagefile</code>)</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> shared</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> pfaults</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> text</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> num_page_faults</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> text</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> pageins</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> data</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> peak_wset</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> lib</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> stack</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> wset</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> data</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> peak_paged_pool</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> dirty</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> paged_pool</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> peak_nonpaged_pool</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> nonpaged_pool</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> pagefile</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> peak_pagefile</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> private</td> 
  </tr> 
 </tbody> 
</table>

*  **rss**: aka “Resident Set Size”, this is the non-swapped physical memory a process has used. On UNIX it matches “top“‘s RES column (see[doc][]). On Windows this is an alias for wset field and it matches “Mem Usage” column of taskmgr.exe.
 *  **vms**: aka “Virtual Memory Size”, this is the total amount of virtual memory used by the process. On UNIX it matches “top“‘s VIRT column (see[doc][]). On Windows this is an alias for pagefile field and it matches “Mem Usage” “VM Size” column of taskmgr.exe.
 *  **shared**: *(Linux)* memory that could be potentially shared with other processes. This matches “top“‘s SHR column (see [doc][]).
 *  **text** *(Linux, BSD)*: aka TRS (text resident set) the amount of memory devoted to executable code. This matches “top“‘s CODE column (see[doc][]).
 *  **data** *(Linux, BSD)*: aka DRS (data resident set) the amount of physical memory devoted to other than executable code. It matches “top“‘s DATA column (see [doc][]).
 *  **lib** *(Linux)*: the memory used by shared libraries.
 *  **dirty** *(Linux)*: the number of dirty pages.

For Windows fields rely on [PROCESS\_MEMORY\_COUNTERS\_EX][PROCESS_MEMORY_COUNTERS_EX] structure doc. Example on Linux:

>>> import psutil
    >>> p = psutil.Process() >>> p.memory_info() pmem(rss=15491072, vms=84025344, shared=5206016, text=2555904, lib=0, data=9891840, dirty=0)

Changed in version 4.0.0: mutiple fields are returned, not only rss and vms.

`memory_info_ex` ()

Same as [`memory_info()`][memory_info] (deprecated).

Warning

deprecated in version 4.0.0; use [`memory_info()`][memory_info] instead.

`memory_full_info` ()

This method returns the same information as [`memory_info()`][memory_info], plus, on some platform (Linux, OSX, Windows), also provides additional metrics (USS, PSS and swap). The additional metrics provide a better representation of “effective” process memory consumption (in case of USS) as explained in detail [here][]. It does so by passing through the whole process address. As such it usually requires higher user privileges than [`memory_info()`][memory_info] and is considerably slower. On platforms where extra fields are not implented this simply returns the same metrics as [`memory_info()`][memory_info].

*  **uss** *(Linux, OSX, Windows)*: aka “Unique Set Size”, this is the memory which is unique to a process and which would be freed if the process was terminated right now.
 *  **pss** *(Linux)*: aka “Proportional Set Size”, is the amount of memory shared with other processes, accounted in a way that the amount is divided evenly between the processes that share it. I.e. if a process has 10 MBs all to itself and 10 MBs shared with another process its PSS will be 15 MBs.
 *  **swap** *(Linux)*: amount of memory that has been swapped out to disk.

Note

uss is probably the most representative metric for determining how much memory is actually being used by a process. It represents the amount of memory that would be freed if the process was terminated right now.

Example on Linux:

>>> import psutil
    >>> p = psutil.Process() >>> p.memory_full_info() pfullmem(rss=10199040, vms=52133888, shared=3887104, text=2867200, lib=0, data=5967872, dirty=0, uss=6545408, pss=6872064, swap=0) >>>

See also [scripts/procsmem.py][scripts_procsmem.py] for an example application.

New in version 4.0.0.

`memory_percent` (*memtype="rss"*)

Compare process memory to total physical system memory and calculate process memory utilization as a percentage. *memtype* argument is a string that dictates what type of process memory you want to compare against. You can choose between the namedtuple field names returned by[`memory_info()`][memory_info] and [`memory_full_info()`][memory_full_info] (defaults to `"rss"`).

Changed in version 4.0.0: added memtype parameter.

`memory_maps` (*grouped=True*)

Return process’s mapped memory regions as a list of namedtuples whose fields are variable depending on the platform. This method is useful to obtain a detailed representation of process memory usage as explained [here][here 1] (the most important value is “private” memory). If *grouped* is `True` the mapped regions with the same *path* are grouped together and the different memory fields are summed. If *grouped* is `False` each mapped region is shown as a single entity and the namedtuple will also include the mapped region’s address space (*addr*) and permission set (*perms*). See[scripts/pmap.py][scripts_pmap.py] for an example application.

<table style="border:1px solid silver; border-collapse:collapse; word-break:break-word">        
 <thead> 
  <tr> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> Linux</th> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> OSX</th> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> Windows</th> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> Solaris</th> 
   <th style="border:1px solid silver; border-collapse:collapse; padding:3px"> FreeBSD</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> rss</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> size</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> private</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> anonymous</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> private</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> pss</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> swapped</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> locked</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> ref_count</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> shared_clean</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> dirtied</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> shadow_count</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> shared_dirty</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> ref_count</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> private_clean</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> shadow_depth</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> private_dirty</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> referenced</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
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  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> anonymous</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
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  </tr> 
  <tr> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> swap</td> 
   <td style="font-size:14px; border:1px solid silver; border-collapse:collapse; padding:3px"> &nbsp;</td> 
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 </tbody> 
</table>

>>> import psutil
    >>> p = psutil.Process() >>> 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='/lib/x8664-linux-gnu/libcrypto.so.0.1', rss=34124, rss=32768, size=2134016, pss=15360, shared_clean=24576, shared_dirty=0, private_clean=0, private_dirty=8192, referenced=24576, anonymous=8192, 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), ...] >>>

Availability: All platforms except OpenBSD and NetBSD.

`children` (*recursive=False*)

Return the children of this process as a list of [`Process`][Process] objects, preemptively checking whether PID has been reused. If recursive is True return all the parent descendants. Example assuming *A == this process*:

A ─┐
       │
       ├─ B (child) ─┐
       │             └─ X (grandchild) ─┐
       │                                └─ Y (great grandchild)
       ├─ C (child)
       └─ D (child)
    
    >>> p.children()
    B, C, D
    >>> p.children(recursive=True)
    B, X, Y, C, D

Note that in the example above if process X disappears process Y won’t be returned either as the reference to process A is lost.

`open_files` ()

Return regular files opened by process as a list of namedtuples including the following fields:

*  **path**: the absolute file name.
 *  **fd**: the file descriptor number; on Windows this is always `-1`.
 *  **position** (*Linux*): the file (offset) position.
 *  **mode** (*Linux*): a string indicating how the file was opened, similarly [open][]‘s `mode` argument. Possible values are `'r'`, `'w'`, `'a'`, `'r+'` and `'a+'`. There’s no distinction between files opened in bynary or text mode (`"b"` or `"t"`).
 *  **flags** (*Linux*): the flags which were passed to the underlying [os.open][] C call when the file was opened (e.g. [os.O\_RDONLY][os.O_RDONLY], [os.O\_TRUNC][os.O_TRUNC], etc).

>>> import psutil
    >>> f = open('file.ext', 'w') >>> p = psutil.Process() >>> p.open_files() [popenfile(path='/home/giampaolo/svn/psutil/setup.py', fd=3, position=0, mode='r', flags=32768), popenfile(path='/var/log/monitd', fd=4, position=235542, mode='a', flags=33793)]

Warning

on Windows this is not fully reliable as due to some limitations of the Windows API the underlying implementation may hang when retrieving certain file handles. In order to work around that psutil on Windows Vista (and higher) spawns a thread and kills it if it’s not responding after 100ms. That implies that on Windows this method is not guaranteed to enumerate all regular file handles (see full [discussion][]).

Warning

on BSD this method can return files with a ‘null’ path due to a kernel bug hence it’s not reliable (see [issue 595][]).

Changed in version 3.1.0: no longer hangs on Windows.

Changed in version 4.1.0: new *position*, *mode* and *flags* fields on Linux.

`connections` (*kind="inet"*)

Return socket connections opened by process as a list of namedtuples. To get system-wide connections use [`psutil.net_connections()`][psutil.net_connections]. Every namedtuple provides 6 attributes:

*  **fd**: the socket file descriptor. This can be passed to [socket.fromfd()][socket.fromfd] to obtain a usable socket object. This is only available on UNIX; on Windows `-1` is always returned.
 *  **family**: the address family, either [AF\_INET][AF_INET], [AF\_INET6][AF_INET6] or [AF\_UNIX][AF_UNIX].
 *  **type**: the address type, either [SOCK\_STREAM][SOCK_STREAM] or [SOCK\_DGRAM][SOCK_DGRAM].
 *  **laddr**: the local address as a `(ip, port)` tuple or a `path` in case of AF\_UNIX sockets.
 *  **raddr**: the remote address as a `(ip, port)` tuple or an absolute `path` in case of UNIX sockets. When the remote endpoint is not connected you’ll get an empty tuple (AF\_INET) or `None` (AF\_UNIX). On Linux AF\_UNIX sockets will always have this set to `None`.
 *  **status**: represents the status of a TCP connection. The return value is one of the [`psutil.CONN_*`][psutil.CONN] constants. For UDP and UNIX sockets this is always going to be [`psutil.CONN_NONE`][psutil.CONN_NONE].

The *kind* parameter is a string which filters for connections that fit the following criteria:

Example:

>>> import psutil
    >>> p = psutil.Process(1694) >>> p.name() 'firefox' >>> p.connections() [pconn(fd=115, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 48776), raddr=('93.186.135.91', 80), status='ESTABLISHED'), pconn(fd=117, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 43761), raddr=('72.14.234.100', 80), status='CLOSING'), pconn(fd=119, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 60759), raddr=('72.14.234.104', 80), status='ESTABLISHED'), pconn(fd=123, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 51314), raddr=('72.14.234.83', 443), status='SYN_SENT')]

`is_running` ()

Return whether the current process is running in the current process list. This is reliable also in case the process is gone and its PID reused by another process, therefore it must be preferred over doing `psutil.pid_exists(p.pid)`.

Note

this will return `True` also if the process is a zombie (`p.status() == psutil.STATUS_ZOMBIE`).

`send_signal` (*signal*)

Send a signal to process (see [signal module][] constants) preemptively checking whether PID has been reused. On UNIX this is the same as`os.kill(pid, sig)`. On Windows only **SIGTERM**, **CTRL\_C\_EVENT** and **CTRL\_BREAK\_EVENT** signals are supported and **SIGTERM** is treated as an alias for [`kill()`][kill].

Changed in version 3.2.0: support for CTRL\_C\_EVENT and CTRL\_BREAK\_EVENT signals on Windows was added.

`suspend` ()

Suspend process execution with **SIGSTOP** signal preemptively checking whether PID has been reused. On UNIX this is the same as `os.kill(pid,signal.SIGSTOP)`. On Windows this is done by suspending all process threads execution.

`resume` ()

Resume process execution with **SIGCONT** signal preemptively checking whether PID has been reused. On UNIX this is the same as `os.kill(pid,signal.SIGCONT)`. On Windows this is done by resuming all process threads execution.

`terminate` ()

Terminate the process with **SIGTERM** signal preemptively checking whether PID has been reused. On UNIX this is the same as `os.kill(pid,signal.SIGTERM)`. On Windows this is an alias for [`kill()`][kill].

`kill` ()

Kill the current process by using **SIGKILL** signal preemptively checking whether PID has been reused. On UNIX this is the same as `os.kill(pid,signal.SIGKILL)`. On Windows this is done by using [TerminateProcess][].

`wait` (*timeout=None*)

Wait for process termination and if the process is a children of the current one also return the exit code, else `None`. On Windows there’s no such limitation (exit code is always returned). If the process is already terminated immediately return `None` instead of raising [`NoSuchProcess`][NoSuchProcess]. If *timeout* is specified and process is still alive raise [`TimeoutExpired`][TimeoutExpired] exception. It can also be used in a non-blocking fashion by specifying `timeout=0` in which case it will either return immediately or raise [`TimeoutExpired`][TimeoutExpired]. To wait for multiple processes use [`psutil.wait_procs()`][psutil.wait_procs].

### Popen class ###

*class*  `psutil.` `Popen` (*\*args*, *\*\*kwargs*)

A more convenient interface to stdlib [subprocess.Popen][]. It starts a sub process and deals with it exactly as when using [subprocess.Popen][] but in addition it also provides all the methods of [`psutil.Process`][Process] class in a single interface. For method names common to both classes such as[`send_signal()`][send_signal], [`terminate()`][terminate] and [`kill()`][kill] [`psutil.Process`][Process] implementation takes precedence. For a complete documentation refer to [subprocess module documentation][].

Note

Unlike [subprocess.Popen][] this class preemptively checks wheter PID has been reused on [`send_signal()`][send_signal], [`terminate()`][terminate] and [`kill()`][kill] so that you can’t accidentally terminate another process, fixing [http://bugs.python.org/issue6973][http_bugs.python.org_issue6973].

>>> import psutil
    >>> from subprocess import PIPE >>> >>> p = psutil.Popen(["/usr/bin/python", "-c", "print('hello')"], stdout=PIPE) >>> p.name() 'python' >>> p.username() 'giampaolo' >>> p.communicate() ('hello\n', None) >>> p.wait(timeout=2) 0 >>>

## Windows services ##

`psutil.` `win_service_iter` ()

Return an iterator yielding a [`WindowsService`][WindowsService] class instance for all Windows services installed.

New in version 4.2.0.

Availability: Windows

`psutil.` `win_service_get` (*name*)

Get a Windows service by name, returning a [`WindowsService`][WindowsService] instance. Raise [`psutil.NoSuchProcess`][NoSuchProcess] if no service with such name exists.

New in version 4.2.0.

Availability: Windows

*class*  `psutil.` `WindowsService`

Represents a Windows service with the given *name*. This class is returned by [`win_service_iter()`][win_service_iter] and [`win_service_get()`][win_service_get] functions and it is not supposed to be instantiated directly.

`name` ()

The service name. This string is how a service is referenced and can be passed to [`win_service_get()`][win_service_get] to get a new [`WindowsService`][WindowsService] instance.

`display_name` ()

The service display name. The value is cached when this class is instantiated.

`binpath` ()

The fully qualified path to the service binary/exe file as a string, including command line arguments.

`username` ()

The name of the user that owns this service.

`start_type` ()

A string which can either be “automatic”, “manual” or “disabled”.

`pid` ()

The process PID, if any, else None. This can be passed to [`Process`][Process] class to control the service’s process.

`status` ()

Service status as a string, which may be either “running”, “paused”, “start\_pending”, “pause\_pending”, “continue\_pending”, “stop\_pending” or“stopped”.

`description` ()

Service long description.

`as_dict` ()

Utility method retrieving all the information above as a dictionary.

New in version 4.2.0.

Availability: Windows

Example code:

>>> import psutil
    >>> list(psutil.win_service_iter()) [<WindowsService(name='AeLookupSvc', display_name='Application Experience') at 38850096>, <WindowsService(name='ALG', display_name='Application Layer Gateway Service') at 38850128>, <WindowsService(name='APNMCP', display_name='Ask Update Service') at 38850160>, <WindowsService(name='AppIDSvc', display_name='Application Identity') at 38850192>, ...] >>> s = psutil.win_service_get('alg') >>> s.as_dict() {'binpath': 'C:\\Windows\\System32\\alg.exe', 'description': 'Provides support for 3rd party protocol plug-ins for Internet Connection Sharing', 'display_name': 'Application Layer Gateway Service', 'name': 'alg', 'pid': None, 'start_type': 'manual', 'status': 'stopped', 'username': 'NT AUTHORITY\\LocalService'}

## Constants ##

`psutil.` `POSIX` `psutil.` `WINDOWS` `psutil.` `LINUX` `psutil.` `OSX` `psutil.` `FREEBSD` `psutil.` `NETBSD` `psutil.` `OPENBSD` `psutil.` `BSD` `psutil.` `SUNOS`

`bool` constants which define what platform you’re on. E.g. if on Windows, *WINDOWS* constant will be `True`, all others will be `False`.

New in version 4.0.0.

`psutil.` `PROCFS_PATH`

The path of the /proc filesystem on Linux and Solaris (defaults to “/proc”). You may want to re-set this constant right after importing psutil in case your /proc filesystem is mounted elsewhere.

Availability: Linux, Solaris

New in version 3.2.3.

Changed in version 3.4.2: also available on Solaris.

`psutil.` `STATUS_RUNNING` `psutil.` `STATUS_SLEEPING` `psutil.` `STATUS_DISK_SLEEP` `psutil.` `STATUS_STOPPED` `psutil.` `STATUS_TRACING_STOP` `psutil.` `STATUS_ZOMBIE` `psutil.` `STATUS_DEAD` `psutil.` `STATUS_WAKE_KILL` `psutil.` `STATUS_WAKING` `psutil.` `STATUS_IDLE` (*OSX*, *FreeBSD*) `psutil.` `STATUS_LOCKED` (*FreeBSD*) `psutil.` `STATUS_WAITING` (*FreeBSD*) `psutil.` `STATUS_SUSPENDED` (*NetBSD*)

A set of strings representing the status of a process. Returned by [`psutil.Process.status()`][psutil.Process.status].

New in version 3.4.1: STATUS\_SUSPENDED (NetBSD)

`psutil.` `CONN_ESTABLISHED` `psutil.` `CONN_SYN_SENT` `psutil.` `CONN_SYN_RECV` `psutil.` `CONN_FIN_WAIT1` `psutil.` `CONN_FIN_WAIT2` `psutil.` `CONN_TIME_WAIT` `psutil.` `CONN_CLOSE` `psutil.` `CONN_CLOSE_WAIT` `psutil.` `CONN_LAST_ACK` `psutil.` `CONN_LISTEN` `psutil.` `CONN_CLOSING` `psutil.` `CONN_NONE` `psutil.` `CONN_DELETE_TCB` (*Windows*) `psutil.` `CONN_IDLE` (*Solaris*) `psutil.` `CONN_BOUND` (*Solaris*)

A set of strings representing the status of a TCP connection. Returned by [`psutil.Process.connections()`][Process.connections] (status field).

`psutil.` `ABOVE_NORMAL_PRIORITY_CLASS` `psutil.` `BELOW_NORMAL_PRIORITY_CLASS` `psutil.` `HIGH_PRIORITY_CLASS` `psutil.` `IDLE_PRIORITY_CLASS` `psutil.` `NORMAL_PRIORITY_CLASS` `psutil.` `REALTIME_PRIORITY_CLASS`

A set of integers representing the priority of a process on Windows (see [MSDN documentation][SetPriorityClass]). They can be used in conjunction with[`psutil.Process.nice()`][nice] to get or set process priority.

Availability: Windows

Changed in version 3.0.0: on Python >= 3.4 these constants are [enums][enum] instead of a plain integer.

`psutil.` `IOPRIO_CLASS_NONE` `psutil.` `IOPRIO_CLASS_RT` `psutil.` `IOPRIO_CLASS_BE` `psutil.` `IOPRIO_CLASS_IDLE`

A set of integers representing the I/O priority of a process on Linux. They can be used in conjunction with [`psutil.Process.ionice()`][ionice] to get or set process I/O priority. *IOPRIO\_CLASS\_NONE* and *IOPRIO\_CLASS\_BE* (best effort) is the default for any process that hasn’t set a specific I/O priority.*IOPRIO\_CLASS\_RT* (real time) means the process is given first access to the disk, regardless of what else is going on in the system.*IOPRIO\_CLASS\_IDLE* means the process will get I/O time when no-one else needs the disk. For further information refer to manuals of [ionice][ionice 1]command line utility or [ioprio\_get][ioprio_get] system call.

Availability: Linux

Changed in version 3.0.0: on Python >= 3.4 thse constants are [enums][enum] instead of a plain integer.

`psutil.` `RLIMIT_INFINITY` `psutil.` `RLIMIT_AS` `psutil.` `RLIMIT_CORE` `psutil.` `RLIMIT_CPU` `psutil.` `RLIMIT_DATA` `psutil.` `RLIMIT_FSIZE` `psutil.` `RLIMIT_LOCKS` `psutil.` `RLIMIT_MEMLOCK` `psutil.` `RLIMIT_MSGQUEUE` `psutil.` `RLIMIT_NICE` `psutil.` `RLIMIT_NOFILE` `psutil.` `RLIMIT_NPROC` `psutil.` `RLIMIT_RSS` `psutil.` `RLIMIT_RTPRIO` `psutil.` `RLIMIT_RTTIME` `psutil.` `RLIMIT_RTPRIO` `psutil.` `RLIMIT_SIGPENDING` `psutil.` `RLIMIT_STACK`

Constants used for getting and setting process resource limits to be used in conjunction with [`psutil.Process.rlimit()`][rlimit]. See [man prlimit][] for further information.

Availability: Linux

`psutil.` `AF_LINK`

Constant which identifies a MAC address associated with a network interface. To be used in conjunction with [`psutil.net_if_addrs()`][psutil.net_if_addrs].

New in version 3.0.0.

`psutil.` `NIC_DUPLEX_FULL` `psutil.` `NIC_DUPLEX_HALF` `psutil.` `NIC_DUPLEX_UNKNOWN`

Constants which identifies whether a NIC (network interface card) has full or half mode speed. NIC\_DUPLEX\_FULL means the NIC is able to send and receive data (files) simultaneously, NIC\_DUPLEX\_FULL means the NIC can either send or receive data at a time. To be used in conjunction with[`psutil.net_if_stats()`][psutil.net_if_stats].

New in version 3.0.0.

## Development guide ##

If you plan on hacking on psutil (e.g. want to add a new feature or fix a bug) take a look at the [development guide][Development guide].

[Link 1]: http://pythonhosted.org/psutil/#psutil-documentation
[Home page]: https://github.com/giampaolo/psutil
[Install]: https://github.com/giampaolo/psutil/blob/master/INSTALL.rst
[Blog]: http://grodola.blogspot.com/search/label/psutil
[Forum]: http://groups.google.com/group/psutil/topics
[Download]: https://pypi.python.org/pypi?:action=display&name=psutil#downloads
[Development guide]: https://github.com/giampaolo/psutil/blob/master/DEVGUIDE.rst
[What_s new]: https://github.com/giampaolo/psutil/blob/master/HISTORY.rst
[2.1.3]: https://pypi.python.org/pypi?name=psutil&version=2.1.3&:action=files
[PyPy]: http://pypy.org/
[cpu_percent]: http://pythonhosted.org/psutil/#psutil.cpu_percent
[psutil.cpu_times_percpu_True]: http://pythonhosted.org/psutil/#psutil.cpu_times
[os.cpu_count]: http://docs.python.org/3/library/os.html#os.cpu_count
[scripts_meminfo.py]: https://github.com/giampaolo/psutil/blob/master/scripts/meminfo.py
[dev_shm]: http://www.cyberciti.biz/tips/what-is-devshm-and-its-practical-usage.html
[GetDriveType]: http://msdn.microsoft.com/en-us/library/aa364939%28v=vs.85%29.aspx
[getfsstat_2]: http://www.manpagez.com/man/2/getfsstat/
[disk_usage.py]: https://github.com/giampaolo/psutil/blob/master/scripts/disk_usage.py
[OSError]: http://docs.python.org/3/library/exceptions.html#OSError
[Python 3.3]: http://bugs.python.org/issue12442
[shutil.disk_usage]: http://docs.python.org/3/library/shutil.html#shutil.disk_usage
[source code]: https://github.com/giampaolo/psutil/blob/3dea30d583b8c1275057edb1b3b720813b4d0f60/psutil/_psposix.py#L123
[iostat doc]: https://www.kernel.org/doc/Documentation/iostats.txt
[scripts_iotop.py]: https://github.com/giampaolo/psutil/blob/master/scripts/iotop.py
[issues _802]: https://github.com/giampaolo/psutil/issues/802
[scripts_nettop.py]: https://github.com/giampaolo/psutil/blob/master/scripts/nettop.py
[socket.fromfd]: http://docs.python.org/library/socket.html#socket.fromfd
[AF_INET]: http://docs.python.org//library/socket.html#socket.AF_INET
[AF_INET6]: http://docs.python.org//library/socket.html#socket.AF_INET6
[AF_UNIX]: http://docs.python.org//library/socket.html#socket.AF_UNIX
[SOCK_STREAM]: http://docs.python.org//library/socket.html#socket.SOCK_STREAM
[SOCK_DGRAM]: http://docs.python.org//library/socket.html#socket.SOCK_DGRAM
[psutil.CONN]: http://pythonhosted.org/psutil/#psutil.CONN_ESTABLISHED
[psutil.CONN_NONE]: http://pythonhosted.org/psutil/#psutil.CONN_NONE
[Process.connections]: http://pythonhosted.org/psutil/#psutil.Process.connections
[netstat.py sample script]: https://github.com/giampaolo/psutil/blob/master/scripts/netstat.py
[psutil.AccessDenied]: http://pythonhosted.org/psutil/#psutil.AccessDenied
[psutil.AF_LINK]: http://pythonhosted.org/psutil/#psutil.AF_LINK
[scripts_ifconfig.py]: https://github.com/giampaolo/psutil/blob/master/scripts/ifconfig.py
[netifaces]: https://pypi.python.org/pypi/netifaces/
[NIC_DUPLEX_FULL]: http://pythonhosted.org/psutil/#psutil.NIC_DUPLEX_FULL
[NIC_DUPLEX_HALF]: http://pythonhosted.org/psutil/#psutil.NIC_DUPLEX_HALF
[NIC_DUPLEX_UNKNOWN]: http://pythonhosted.org/psutil/#psutil.NIC_DUPLEX_UNKNOWN
[process_iter]: http://pythonhosted.org/psutil/#psutil.process_iter
[Process]: http://pythonhosted.org/psutil/#psutil.Process
[psutil.pids]: http://pythonhosted.org/psutil/#psutil.pids
[Process.name]: http://pythonhosted.org/psutil/#psutil.Process.name
[NoSuchProcess]: http://pythonhosted.org/psutil/#psutil.NoSuchProcess
[Process.wait]: http://pythonhosted.org/psutil/#psutil.Process.wait
[os.getpid]: http://docs.python.org/library/os.html#os.getpid
[ZombieProcess]: http://pythonhosted.org/psutil/#psutil.ZombieProcess
[hash]: http://docs.python.org/2/library/functions.html#hash
[set_s]: http://docs.python.org/2/library/stdtypes.html#types-set
[nice]: http://pythonhosted.org/psutil/#psutil.Process.nice
[ionice]: http://pythonhosted.org/psutil/#psutil.Process.ionice
[cpu_affinity]: http://pythonhosted.org/psutil/#psutil.Process.cpu_affinity
[rlimit]: http://pythonhosted.org/psutil/#psutil.Process.rlimit
[children]: http://pythonhosted.org/psutil/#psutil.Process.children
[parent]: http://pythonhosted.org/psutil/#psutil.Process.parent
[suspend]: http://pythonhosted.org/psutil/#psutil.Process.suspend
[resume]: http://pythonhosted.org/psutil/#psutil.Process.resume
[send_signal]: http://pythonhosted.org/psutil/#psutil.Process.send_signal
[terminate]: http://pythonhosted.org/psutil/#psutil.Process.terminate
[kill]: http://pythonhosted.org/psutil/#psutil.Process.kill
[is_running]: http://pythonhosted.org/psutil/#psutil.Process.is_running
[UTC]: http://en.wikipedia.org/wiki/Coordinated_universal_time
[psutil.STATUS]: http://pythonhosted.org/psutil/#psutil.STATUS_RUNNING
[os.getresuid]: http://docs.python.org//library/os.html#os.getresuid
[os.getresgid]: http://docs.python.org//library/os.html#os.getresgid
[niceness]: http://pythonhosted.org/psutil/blogs.techrepublic.com.com/opensource/?p=140
[Python 3.3 1]: http://bugs.python.org/issue10784
[os.getpriority]: http://docs.python.org/3/library/os.html#os.getpriority
[os.setpriority]: http://docs.python.org/3/library/os.html#os.setpriority
[GetPriorityClass]: http://msdn.microsoft.com/en-us/library/ms683211%28v=vs.85%29.aspx
[SetPriorityClass]: http://msdn.microsoft.com/en-us/library/ms686219%28v=vs.85%29.aspx
[psutil._PRIORITY_CLASS]: http://pythonhosted.org/psutil/#psutil.ABOVE_NORMAL_PRIORITY_CLASS
[process I_O niceness]: http://friedcpu.wordpress.com/2007/07/17/why-arent-you-using-ionice-yet/
[psutil.IOPRIO_CLASS]: http://pythonhosted.org/psutil/#psutil.IOPRIO_CLASS_NONE
[enum]: https://docs.python.org/3/library/enum.html#module-enum
[man prlimit]: http://linux.die.net/man/2/prlimit
[psutil.RLIMIT]: http://pythonhosted.org/psutil/#psutil.RLIMIT_INFINITY
[resource.getrlimit]: http://docs.python.org/library/resource.html#resource.getrlimit
[resource.setrlimit]: http://docs.python.org/library/resource.html#resource.setrlimit
[proc filesysem documentation]: https://www.kernel.org/doc/Documentation/filesystems/proc.txt
[explanation]: http://stackoverflow.com/questions/556405/
[os.times]: http://docs.python.org//library/os.html#os.times
[CPU affinity]: http://www.linuxjournal.com/article/6799?page=0,0
[doc]: http://linux.die.net/man/1/top
[PROCESS_MEMORY_COUNTERS_EX]: http://msdn.microsoft.com/en-us/library/windows/desktop/ms684874%28v=vs.85%29.aspx
[memory_info]: http://pythonhosted.org/psutil/#psutil.Process.memory_info
[here]: http://grodola.blogspot.com/2016/02/psutil-4-real-process-memory-and-environ.html
[scripts_procsmem.py]: https://github.com/giampaolo/psutil/blob/master/scripts/procsmem.py
[memory_full_info]: http://pythonhosted.org/psutil/#psutil.Process.memory_full_info
[here 1]: http://bmaurer.blogspot.it/2006/03/memory-usage-with-smaps.html
[scripts_pmap.py]: https://github.com/giampaolo/psutil/blob/master/scripts/pmap.py
[open]: https://docs.python.org/3/library/functions.html#open
[os.open]: https://docs.python.org/2/library/os.html#os.open
[os.O_RDONLY]: https://docs.python.org/3/library/os.html#os.O_RDONLY
[os.O_TRUNC]: https://docs.python.org/3/library/os.html#os.O_TRUNC
[discussion]: https://github.com/giampaolo/psutil/pull/597
[issue 595]: https://github.com/giampaolo/psutil/pull/595
[psutil.net_connections]: http://pythonhosted.org/psutil/#psutil.net_connections
[signal module]: http://docs.python.org//library/signal.html
[TerminateProcess]: http://msdn.microsoft.com/en-us/library/windows/desktop/ms686714%28v=vs.85%29.aspx
[TimeoutExpired]: http://pythonhosted.org/psutil/#psutil.TimeoutExpired
[psutil.wait_procs]: http://pythonhosted.org/psutil/#psutil.wait_procs
[subprocess.Popen]: http://docs.python.org/library/subprocess.html#subprocess.Popen
[subprocess module documentation]: http://docs.python.org/library/subprocess.html
[http_bugs.python.org_issue6973]: http://bugs.python.org/issue6973
[WindowsService]: http://pythonhosted.org/psutil/#psutil.WindowsService
[win_service_iter]: http://pythonhosted.org/psutil/#psutil.win_service_iter
[win_service_get]: http://pythonhosted.org/psutil/#psutil.win_service_get
[psutil.Process.status]: http://pythonhosted.org/psutil/#psutil.Process.status
[ionice 1]: http://linux.die.net/man/1/ionice
[ioprio_get]: http://linux.die.net/man/2/ioprio_get
[psutil.net_if_addrs]: http://pythonhosted.org/psutil/#psutil.net_if_addrs
[psutil.net_if_stats]: http://pythonhosted.org/psutil/#psutil.net_if_stats