Launch a shell command with in a python script, wait for the termination and return to the script

subprocess: The subprocess module allows you to spawn new processes, connect to their input/output/error pipes, and obtain their return codes.

http://docs.python.org/library/subprocess.html

Usage:

import subprocessprocess = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE)process.wait()print process.returncode

You can use subprocess.Popen. There's a few ways to do it:

import subprocesscmd = ['/run/myscript', '--arg', 'value']p = subprocess.Popen(cmd, stdout=subprocess.PIPE)for line in p.stdout:    print linep.wait()print p.returncode

Or, if you don't care what the external program actually does:

cmd = ['/run/myscript', '--arg', 'value']subprocess.Popen(cmd).wait()

The subprocess module has come along way since 2008. In particular check_call and check_output make simple subprocess stuff even easier. The check_* family of functions are nice it that they raise an exception if something goes wrong.

import osimport subprocessfiles = os.listdir('.')for f in files:   subprocess.check_call( [ 'myscript', f ] )

Any output generated by myscript will display as though your process produced the output (technically myscript and your python script share the same stdout). There are a couple of ways to avoid this.

• check_call( [ 'myscript', f ], stdout=subprocess.PIPE )
  The stdout will be supressed (beware if myscript produces more that 4k of output). stderr will still be shown unless you add the option stderr=subprocess.PIPE.
• check_output( [ 'myscript', f ] )
check_output returns the stdout as a string so it isnt shown. stderr is still shown unless you add the option stderr=subprocess.STDOUT.