channel.recv() problem about paramiko-expect HOT 7 OPEN

timeout = 30
display = False
cmd = passwd
password = mynewpassword
exp_dict = {
                "New password: ":"{}".format(password), 
                "Retype new password: ":"{}".format(password), 
                "passwd: all authentication tokens updated successfully.":"\n"
            }
prompts = []
try:
    for prompt in exp_dict:
        prompts.append(prompt)
except Exception:
    print('Error building prompts list from exp_dict!')
    return '!! Failed !!'

try:
    # Create a new SSH client object
    client = paramiko.SSHClient()

    # Set SSH key parameters to auto accept unknown hosts
    client.load_system_host_keys()
    client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

    # Connect to the host
    client.connect(hostname=server, username=myusername, password=mypassword)

    # Create a client interaction class which will interact with the host
    with SSHClientInteraction(client, timeout=timeout, display=display) as interact:           
        interact.send(cmd)
        for prompt in prompts:
            interact.expect(prompts) #expect a prompt for our prompts list
            interact.send(exp_dict[interact.last_match]) #send the value assinged to prompt key
        interact.send('exit')
        interact.expect()
        status = 'Success'
except Exception:
    status = '!! Failed !!'
    pass
finally:
    try:
        client.close()
    except:
        pass

return status