Using telnetlib I pull routing info from my router and want to extract the WAN IP address using a pattern. The output of the telnet session is in a variable with lines separated by \n. 

The stuff from the telnet session.

```
l= tn.read_all()
>>> l
'\r\nip -f inet addr\r\nexit\r\nadmin4asus@RT-AC68U:/tmp/home/root# ip -f inet addr\r\n1: lo: <LOOPBACK,MULTICAST,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN \r\n    inet 127.0.0.1/8 brd 127.255.255.255 scope host lo\r\n2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000\r\n    inet 24.6.29.214/21 brd 24.6.31.255 scope global eth0\r\n7: br0: <BROADCAST,MULTICAST,ALLMULTI,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN \r\n    inet 192.168.11.1/24 brd 192.168.11.255 scope global br0\r\n8: tun21: <POINTOPOINT,MULTICAST,NOARP,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 100\r\n    inet 10.8.0.1 peer 10.8.0.2/32 scope global tun21\r\nadmin4asus@RT-AC68U:/tmp/home/root# exit\r\n'
>>> 

```

Now my code.

```
l= tn.read_all()
for line in l.split('\n'):
    match= re.findall( r'([0-9]+(?:\.[0-9]+){3}).*scope global eth0', line)
    if match is not None:
        print('Found ' + line)

```

I would have expected the one line that matches to print.

```
Found     inet 24.6.29.214/21 brd 24.6.31.255 scope global eth0

```

But I get the find everywhere.

```
Found 
Found ip -f inet addr
Found exit
Found admin4asus@RT-AC68U:/tmp/home/root# ip -f inet addr
Found 1: lo: <LOOPBACK,MULTICAST,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
Found     inet 127.0.0.1/8 brd 127.255.255.255 scope host lo
Found 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
Found     inet 24.6.29.214/21 brd 24.6.31.255 scope global eth0
Found 7: br0: <BROADCAST,MULTICAST,ALLMULTI,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN 
Found     inet 192.168.11.1/24 brd 192.168.11.255 scope global br0
Found 8: tun21: <POINTOPOINT,MULTICAST,NOARP,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 100
Found     inet 10.8.0.1 peer 10.8.0.2/32 scope global tun21
Found admin4asus@RT-AC68U:/tmp/home/root# exit
Found 

```

I can't figure out why my code is failing. If the experts have a better method (with explanation) that would be great.

**Edit :**

Jan's answer is surely more pythonic, but my lack of knowledge of python makes me prefer vks which is easier to understand for me. I gave both a '^' and will mark vks as preferred (in the sense 'preferred by me').

I ended up using '\r\n' in the 'split' cmd and following code.

```
def get_asus_wan_ip():
    "Gets WAN IP from ASUS router"

    import telnetlib
    import re

    ASUS_IP=   '192.168.1.1'
    ASUS_USER= 'xxxxxxxx'
    ASUS_PASS= 'yyyyyyyy'
    tn = telnetlib.Telnet(ASUS_IP)

    tn.read_until("login: ")
    tn.write(ASUS_USER + "\n")
    tn.read_until("Password: ")
    tn.write(ASUS_PASS + "\n")
    tn.write("ifconfig eth0\n")
    tn.write("exit\n")
    l= tn.read_all()
    for line in l.split('\r\n'):
        match= re.findall( r'^\s+inet addr:([0-9]+(?:\.[0-9]+){3}).*', line)
        if match:
            break

    wan_ip= match[0]
    return wan_ip

```