#!/usr/bin/env python3
 
import re
 
ifname = 'file.txt'
 
pat = r';(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3});'
 
lst = []
with open(ifname, encoding='utf-8') as fin:
    for line in fin:
        match = re.search(pat, line)
        match and lst.append(match.group(1))
 
print(lst[:10])
print(len(lst))

[guest@localhost txtip]$ head -5 file.txt
12345;127.0.0.1;6789
12345;192.168.0.1;6789
12345;192.168.0.2;6789
12345;192.168.0.3;6789
12345;127.0.0.1;6789
[guest@localhost txtip]$ wc file.txt
  9600   9600 216000 file.txt
[guest@localhost txtip]$ ./txtip.py 
['127.0.0.1', '192.168.0.1', '192.168.0.2', '192.168.0.3', '127.0.0.1', '192.168.0.1', '192.168.0.2', '192.168.0.3', '127.0.0.1', '192.168.0.1']
9600
[guest@localhost txtip]$

#!/usr/bin/env python3
 
import re
 
ifname = 'file.txt'
 
pat = r';(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3});'
 
with open(ifname, encoding='utf-8') as fin:
    lst = [i.group(1) for i in filter(None, map(re.compile(pat).search, fin))]
 
print(lst[:10])
print(len(lst))