Read list of IP addresses from file and return a network

[dflick]

I have been trying for hours using Google and stack overflow to read a list of IP addresses and return networks. The ip address command works in the Python shell but seems to be tripping over the imported list. I have tried stripping the new line and reading the file in multiple different ways but I keep getting an error returned. I am sure it is something with how I am reading the file in but I just can't figure it out.

Here is the current code. Let's call it revision number 4186!

import ipaddress
def process(line):
    # Output network with mask bits (192.168.0.0/24)
    try:
        return ipaddress.IPv4Interface(line).network
    except Exception:
        return print("FAIL_OR_EMPTY")
with open('ipaddrlong.txt', 'r') as f:
    for line in f:
        process(line)

and the input file called looks like this. There is only the data and a newline (/n).

192.168.252.146/24
192.168.252.158/24
192.168.252.203/24
192.168.252.209/24
If I change the return line to a simple print, it looks fine to me. There are no extra spaces or characters.

'192.168.252.146/24', '192.168.252.158/24', '192.168.252.203/24', '192.168.252.209/24'
And when I try the command from the shell, it seems to work fine:

>>> x="192.168.0.1/24"
>>> ipaddress.IPv4Interface(x).network
IPv4Network('192.168.0.0/24')

But when I run the script the exception "FAIL_OR_EMPTY" is returned. I tried strip() but since there are no extra spaces, that did not help.