telnet from ssh tunnel

[oldfart]

Trying to get data (mainly temperature) from a UniFi Switch 16 POE-150W.
Have to first enter the switch with ssh, then telnet into the local host, then issue a "show env" command.
I am having problems getting a return of data after the telnet command. Here's how far I got:

##first install pexpect .. pip install pexpect

from pexpect import pxssh
import getpass
import time
import sys
import subprocess

try:
    s = pxssh.pxssh()
    hostname = '192.168.1.7'
    username = 'u-name'
    password = 'p-word'
    s.login(hostname, username, password)
#just to prove we are logged into ssh tunnel
    s.sendline('ls')
    s.prompt()
    print(s.before)

# telnet into the switch	
    s.sendline('telnet localhost')
    time.sleep(.5) # just wait a bit
    print(sys.stdout)
#does not work
#    for line in sys.stdout:
#	    print(line)

#this is the command to get temperature and other data    
    s.sendline('show env\n')
    print(sys.stdout)
 
    s.logout()
except pxssh.ExceptionPxssh as e:
    print("pxssh failed on login.")
    print(e)