Question

How do I pass an argument to the system shell in Python and get the output back as an array or string?

Answer 1

os.system is not designed to do that; os.popen is. Both have been obsoleted by the subprocess module, which should be used for writing new code. To capture the output of a shell command, you would instantiate a subprocess.Popen object and call communicate() to retrieve its output.

In addition to the above, the utility function check_output, new in Python 2.7, is a plugin-replacement for shell backquotes, i.e. you pass it the command to execute and get back the output as a string:

>>> subprocess.check_output(['ls', '-a'])
'.\n..\n'