How do you stop the output from subprocess.Popen from being output? Printing can sometimes be slow if there is a great deal of it.
In Python 3.3+ you could use subprocess.DEVNULL, to suppress the output:
from subprocess import DEVNULL, STDOUT, check_call check_call([cmd, arg1, arg2], stdout=DEVNULL, stderr=STDOUT)
Remove stderr=STDOUT if you don't want to suppress stderr also.
stderr=STDOUT
stderr