Python on Windows - how to wait for multiple child processes?

Question

How to wait for multiple child processes in Python on Windows, without active wait (polling)? Something like this almost works for me:

proc1 = subpr         


        

Answer 1

You can use psutil:

>>> import subprocess
>>> import psutil
>>> 
>>> proc1 = subprocess.Popen(['python','mytest.py'])
>>> proc2 = subprocess.Popen(['python','mytest.py'])    
>>> ls = [psutil.Process(proc1.pid), psutil.Process(proc2.pid)]
>>>
>>> gone, alive = psutil.wait_procs(ls, timeout=3)

'gone' and 'alive' are lists indicating which processes are gone and which ones are still alive.

Optionally you can specify a callback which gets invoked every time one of the watched processes terminates:

>>> def on_terminate(proc):
...     print "%s terminated" % proc
...
>>> gone, alive = psutil.wait_procs(ls, timeout=3, callback=on_terminate)