Stuck on splitting up a variable in a template

[Daniel Flick]

The following works on a Python command line

CELLULAR='1.2.3.4'

OCTETS=CELLULAR_IP.split('.')

FOURTH_OCTET=OCTETS[3]

T101_IP='10.1.1.'+FOURTH_OCTET

T102_IP='10.1.2.'+FOURTH_OCTET

T103_IP='10.1.3.'+FOURTH_OCTET

T104_IP='10.1.4.'+FOURTH_OCTET

But I am having all kinds of trouble doing this in a Mako template.  What I am trying to accomplish is to pass the template an IP address in a variable and to grab the last octet of that IP and use it to create 4 other IPs.  I thought I could put this in a block like this:

<%

OCTETS=CELLULAR_IP.split('.')

FOURTH_OCTET=OCTETS[3]

T101_IP='10.1.1.'+FOURTH_OCTET

T102_IP='10.1.2.'+FOURTH_OCTET

T103_IP='10.1.3.'+FOURTH_OCTET

T104_IP='10.1.4.'+FOURTH_OCTET

%>

But I get "list index out of range" error.  I think this may also be causing some issues with variable scoping as well which I am trying to wrap my head around.

I also tried to define a function to do this but my limited Python abilities are preventing me for succeeding.

def get_octets(ip_string):

    try:

        OCTETS=CELLULAR_IP.split('.')

        return FOURTH_OCTET=OCTETS[3]

    except ValueError:

        return 0

Any ideas on what I should be looking at to accomplish this?