How to check if there exists a process with a given pid in Python?

Question

Is there a way to check to see if a pid corresponds to a valid process? I\'m getting a pid from a different source other than from os.getpid() and I need to che

Answer 1

In Python 3.3+, you could use exception names instead of errno constants. Posix version:

import os

def pid_exists(pid): 
    if pid < 0: return False #NOTE: pid == 0 returns True
    try:
        os.kill(pid, 0) 
    except ProcessLookupError: # errno.ESRCH
        return False # No such process
    except PermissionError: # errno.EPERM
        return True # Operation not permitted (i.e., process exists)
    else:
        return True # no error, we can send a signal to the process