Python check shell return

To get both the process output and the returned code:

from subprocess import Popen, PIPE

p = Popen(["ls", "non existent"], stdout=PIPE)
output = p.communicate()[0]
print(p.returncode)
subprocess.CalledProcessError is a class. To access returncode use the exception instance:

from subprocess import CalledProcessError, check_output

try:
    output = check_output(["ls", "non existent"])
    returncode = 0
except CalledProcessError as e:
    output = e.output
    returncode = e.returncode

print(returncode)