Cross-platform way to get PIDs by process name in python

Several processes with the same name are running on host. What is the cross-platform way to get PIDs of those processes by name using python or jython?

1. I want something like pidof but in python. (I don't have pidof anyway.)
2. I can't parse /proc because it might be unavailable (on HP-UX).
3. I do not want to run os.popen('ps') and parse the output because I think it is ugly (field sequence may be different in different OS).
4. Target platforms are Solaris, HP-UX, and maybe others.

You can use psutil (https://github.com/giampaolo/psutil), which works on Windows and UNIX:

import psutil

PROCNAME = "python.exe"

for proc in psutil.process_iter():
    if proc.name() == PROCNAME:
        print(proc)

On my machine it prints:

<psutil.Process(pid=3881, name='python.exe') at 140192133873040>

EDIT 2017-04-27 - here's a more advanced utility function which checks the name against processes' name(), cmdline() and exe():

import os
import psutil

def find_procs_by_name(name):
    "Return a list of processes matching 'name'."
    assert name, name
    ls = []
    for p in psutil.process_iter():
        name_, exe, cmdline = "", "", []
        try:
            name_ = p.name()
            cmdline = p.cmdline()
            exe = p.exe()
        except (psutil.AccessDenied, psutil.ZombieProcess):
            pass
        except psutil.NoSuchProcess:
            continue
        if name == name_ or cmdline[0] == name or os.path.basename(exe) == name:
            ls.append(p)
    return ls

There's no single cross-platform API, you'll have to check for OS. For posix based use /proc. For Windows use following code to get list of all pids with coresponding process names

from win32com.client import GetObject
WMI = GetObject('winmgmts:')
processes = WMI.InstancesOf('Win32_Process')
process_list = [(p.Properties_("ProcessID").Value, p.Properties_("Name").Value) for p in processes]

You can then easily filter out processes you need. For more info on available properties of Win32_Process check out Win32_Process Class

import psutil

process = filter(lambda p: p.name() == "YourProcess.exe", psutil.process_iter())
for i in process:
  print i.name,i.pid

Give all pids of "YourProcess.exe"

A note on ThorSummoner's comment

process = [proc for proc in psutil.process_iter() if proc.name == "YourProcess.exe"].

I have tried it on Debian with Python 3, I think it has to be proc.name() instead of proc.name.

First, Windows (in all it's incarnations) is a non-standard OS.

Linux (and most proprietary unixen) are POSIX-compliant standard operating systems.

The C libraries reflect this dichotomy. Python reflects the C libraries.

There is no "cross-platform" way to do this. You have to hack up something with ctypes for a particular release of Windows (XP or Vista)

I don't think you will be able to find a purely python-based, portable solution without using /proc or command line utilities, at least not in python itself. Parsing os.system is not ugly - someone has to deal with the multiple platforms, be it you or someone else. Implementing it for the OS you are interested in should be fairly easy, honestly.

There isn't, I'm afraid. Processes are uniquely identified by pid not by name. If you really must find a pid by name, then you will have use something like you have suggested, but it won't be portable and probably will not work in all cases.

If you only have to find the pids for a certain application and you have control over this application, then I'd suggest changing this app to store its pid in files in some location where your script can find it.

For jython, if Java 5 is used, then you can get the Java process id as following:

from java.lang.management import *
pid = ManagementFactory.getRuntimeMXBean().getName()

Just use:

def get_process_by_name(name):
    import re, psutil
    ls = list()
    for p in psutil.process_iter():
        if hasattr(p, 'name'):
            if re.match(".*" + name + ".*", p.name()):
                ls.append(p)
    return ls

returns Process object