Почему paramico не выводит список файлов?

import paramiko 

host = '***.***.***.***'
user = '********'
secret = '********'
port = 22

client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
client.connect(hostname=host, username=user, password=secret, port=port)
stdin, stdout, stderr = client.exec_command('cd /')
stdin, stdout, stderr = client.exec_command('ls')
data = stdout.read() + stderr.read()
print data
client.close()

stdin, stdout, stderr = client.exec_command('ping localhost -c 3')
data = stdout.read() + stderr.read()
print data