Popen.returncode not working in Python?

Question

I have a price of code which transfers file from server to local machine. However, the directory the user enters may not be always correct. If the user enters the incorrect directory I am trying to show the error. If the returncode is not None I will show the error. But this doesn't work. No matter what the program throws it always go to else part.

#!/usr/bin/python

import subprocess



result = subprocess.Popen(['sshpass', '-p', 'password', 'rsync', '-avz', '--info=progress2', 'username@host_name:/file_name', '/home/zurelsoft/test'], 
                                    stdout=subprocess.PIPE)

if result.returncode != None:
    print "Directory Incorrect"

else:
    print "Done"
    print result

Answer 1

subprocess.Popen returns an object (result variable in your case). You need to call the poll or the wait method of this object to set the returncode status. Then you can check the result.returncode

See http://docs.python.org/2/library/subprocess.html#subprocess.Popen.returncode

The child return code, set by poll() and wait() (and indirectly by communicate()). A None value indicates that the process hasn’t terminated yet.