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

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

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