os.system does not give you any output from the command. I would do either of the following:
- Use Popen
from subprocess import Popen,PIPE
p = Popen("ping -n 1 www.google.com",stdout = PIPE)
output,err = p.communicate("")
print output[output.find("time")+5:output.find("TTL")-3]
Or
2. Use a module, depending on your goals