Keep job running after script stopped by CTRL+C

Question

I'm running an example script here:

os.system("xterm &")
while 1:
    time.sleep(1)

python opens xterm, but after I stop the script by CTRL+C the xterm closes.

if I run

os.system("xterm &")

only, script ends and terminal keeps open.

How do I do than even if I terminate script by CTRL+C, the terminal will keep open?