import paramiko
sftp = paramiko.SSHClient()

hostname = "sftp.host.com"
port = 8022
username = "sftplogin"

k = paramiko.RSAKey.from_private_key_file("private.pem", password="XXX")
sftp.set_missing_host_key_policy(paramiko.AutoAddPolicy())
print "Connecting..."
sftp.connect(hostname, port, username=username, pkey=k )
print "Connected to: " + hostname + ":" + port
print sftp.getcwd()
sftp.close()