subprocess.check_output return code

You can get the error code and results from the exception that is raised.

This can be done through the fields returncode and output.

For example:

import subprocess

try:
    grepOut = subprocess.check_output("grep " + "test" + " tmp", shell=True)                       
except subprocess.CalledProcessError as grepexc:                                                                                                   
    print("error code", grepexc.returncode, grepexc.output)