I'm not sure about osx, but I know linux uses a proc virtual filesystem. ( freebsd is probably closer, and it doesn't either but you can mount it via mount_linprocfs none /proc)
But if you know if you have a proc file system, you can check it to see if you are under power... IE if I remember right, on my laptop it would be '/proc/acpi/battery/BAT1' >From there I would grep / sed it until I got the results I wanted, then do if os.popen("cat /proc[...]") == 'power': [program] else: print "not plugged in" Not the prettiest of solutions, but it's worth a shot -- http://mail.python.org/mailman/listinfo/python-list