kill process

http://stackoverflow.com/questions/2940858/kill-process-by-name-in-python

>>> import subprocess, signal
>>> p = subprocess.Popen(['ps', '-A'], stdout=subprocess.PIPE)
>>> out, err = p.communicate()

gives you ps -A's output in the out variable (a string). You can break it down into lines and loop on them...:

>>> for line in out.splitlines():
...   if 'iChat' in line:
...     pid = int(line.split(None, 1)[0])
...     os.kill(pid, signal.SIGKILL)
...