AttributeError: 'NoneType' object has no attribute 'open_session'"
attributeerror, paramiko, python, ssh
Solution
I had the same thing. I found out it occurred when I closed my client in some previous code. I don't know if that is/was your issue but the error wasn't very informative.
Problem
When running the following function: ``` def conEnclosure(): freebay = open("freebay", "w+") ssh = paramiko.SSHClient() ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) password = getpass.getpass("Enter the password for infra: ") for host in open("full.json", "r"): print host ssh.connect("%s" % host, username="infra", password="%s" % password) stdin, stdout, stderr = ssh.exec_command("show server info all") ``` I received the following error: ``` Traceback (most recent call last): File "./findbay_v2.py", line 53, in <module> conEnclosure() File "./findbay_v2.py", line 41, in conEnclosure ssh.exec_command("show server info all") File "build/bdist.macosx-10.9-intel/egg/paramiko/client.py", line 364, in exec_command AttributeError: 'NoneType' object has no attribute 'open_session' ``` However, when running in python shell the following commands: ``` >>> import paramiko >>> ssh = paramiko.SSHClient() >>> ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) >>> ssh.connect("host", username="xxx", password="xxx") >>> stdin, stdout, stderr = ssh.exec_command("show server info all") ``` Everything went as expected, only when I transform it in the above function in a file.py is that the error occurs. Does anyone have any idea what it might be?