Starting a subprocess from Python

subprocess is a convenient way to fork a new process on Windows/Unix/etc. It obsoletes previous methods such as commands (which does not support Windows) and os.system()/os.popen*/os.spawn*

Here is an example:
import subprocess
cmd_lst = ['exec_file', 'arg1', 'arg2', ...]
subprocess.call(cmd_lst) #return the value returned by the callee
subprocess.check_call(cmd_lst) #return if the callee exits with 0, otherwise raise an error