list is printing incorrectly..

[anna]

Hi All,

Below is the my function, which telnet to devices post checking reachability, after login, I am gathering interface status and if interface name start with Fa0 and status in 'up', storing to dict, later appended to list.
However post checking interface and status, its printing correctly, but list is printing incorrect details.

def open_telnet_new(reachable_sw):
   timeout = 120
   sr_no = 0
   switch_port_dict = {}
   interface_list = []
   try:
        session = telnetlib.Telnet(reachable_sw, 23, timeout)
       # session.set_debuglevel(2)
        time.sleep(1)
        session.read_until(b"Username:")
        session.write((user+"\r").encode('ascii'))
        time.sleep(2)
        session.read_until(b"Password:",2)
        session.write((password + "\r").encode('ascii'))
        time.sleep(2)
        session.read_until(b">")
        session.write("term len 0".encode('ascii') + b"\r")
        session.read_until(b">")
        session.write("show int desc".encode('ascii') + b"\r")
        #output = session.read_all()
        output = session.read_until(">".encode('ascii'), timeout )
        #print(type(output))
        for line in output.decode('utf-8').split('\n')[2:]:
            if '>' in line:
                  continue
            else:
                newline = re.sub('\s{2,}',' ',line).replace('admin down','admin_down').strip().split(' ')
                interface = newline[0]
                status = newline[1]
                if interface.startswith('Fa0') and status == 'up':
                   print(reachable_sw,interface,status)
                   #if status =='up':
                    #print('yes')
                   switch_port_dict['switch_ip'] = reachable_sw
                   switch_port_dict['port'] = interface
                   interface_list.append(switch_port_dict)
                    #interface_list.append(reachable_sw)
                    #print(reachable_sw,interface_list)
                else:
                    continue
        for interfaces in  interface_list:
            #for ports in interfaces:
             print(interfaces['switch_ip'],interfaces['port'])

output while printing list which is incorrect.

Output:
172.21.212.67 Fa0/22
172.21.212.67 Fa0/22
172.21.212.67 Fa0/22
172.21.241.227 Fa0/24
172.21.241.227 Fa0/24
172.21.241.227 Fa0/24
172.21.241.227 Fa0/24
172.21.226.83 Fa0/24
172.21.226.83 Fa0/24
172.21.226.83 Fa0/24
172.21.226.83 Fa0/24
172.21.236.99 Fa0/24
172.21.236.99 Fa0/24
172.21.236.99 Fa0/24
172.21.236.99 Fa0/24
172.21.236.99 Fa0/24
172.21.236.99 Fa0/24
172.21.236.99 Fa0/24
172.21.212.51 Fa0/23
172.21.212.51 Fa0/23
172.21.202.51 Fa0/22
172.21.202.51 Fa0/22

correct output without list.

Output:
172.21.236.99 Fa0/1 up
172.21.236.99 Fa0/2 up
172.21.236.99 Fa0/7 up
172.21.236.99 Fa0/8 up
172.21.236.99 Fa0/22 up
172.21.236.99 Fa0/23 up
172.21.236.99 Fa0/24 up
172.21.241.227 Fa0/17 up
172.21.241.227 Fa0/21 up
172.21.241.227 Fa0/23 up
172.21.241.227 Fa0/24 up
172.21.212.67 Fa0/18 up
172.21.212.67 Fa0/19 up
172.21.212.67 Fa0/22 up
172.21.226.83 Fa0/5 up
172.21.226.83 Fa0/21 up
172.21.226.83 Fa0/23 up
172.21.226.83 Fa0/24 up
172.21.202.51 Fa0/19 up
172.21.202.51 Fa0/22 up
172.21.212.51 Fa0/20 up
172.21.212.51 Fa0/23 up

[ichabod801]

You are appending the same dictionary every time. Unless you do an explicit copy of a dictionary, whenever you modify the dictionary, you modify every other instance of the dictionary you left laying about. That's because the variables are just pointing to the (same) dictionary, not hosting independent versions of it.

I would just condense lines 34-36 into one line: interface_list.append({'switch_ip': reachable_sw, 'port': interface}).