How to determine subprocess.Popen() failed when shell=True

Question

Windows version of Python 2.6.4: Is there any way to determine if subprocess.Popen() fails when using shell=True?

Popen() successfully fails when shell=False

Answer 1

returncode will work, although it will be None until you've called p.poll(). poll() itself will return the error code, so you can just do

if a.poll() != 0:
    print ":("