http://code.google.com/p/psutil/
psutil is a module providing an interface for retrieving information on all running processes and system utilization (CPU, memory, disks, network, users) in a portable way by using Python, implementing many functionalities offered by command line tools such as:
ps
top
df
kill
free
lsof
netstat
ifconfig
nice
ionice
iostat
iotop
uptime
pidof
tty
who
taskset
pmap