3rd command never executed in remote machine using paramiko

[mandalmanas786 at gmail.com]

I have written below code to run 3 command in remote server interactively
But when i checked 3rd command never executed and code stuck here is my code

def execute():
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('ipaddress',username='user', password='pw')

chan=ssh.invoke_shell()    # start the shell before sending commands

chan.send('cd /path to folder/test')
chan.send('\n')
time.sleep(3)    
chan.send("ls -l")
chan.send('\n')
buff=''
while not buff.endswith(">"):
        resp = chan.recv(9999)
       # code stuck here after 'path to folder/test >' comes in shell prompt
        buff+=resp
        print resp

print "test"
chan.send("ls -lh")
chan.send('\n')
time.sleep(5) 
buff=''
while not buff.endswith(">"):
    resp = chan.recv(9999)
    buff+=resp
    print resp         

if __name__ == "__main__":
    execute()           
When i ran i got output of ls -l but ls -lh never executed my code stuck in first while loop. Anyone please help to resolve my issue

When i reduced bytes to read size then it executed 3rd script.