ipaddress.IPv4Network

[buran]

Here is my second version of it

import ipaddress
import csv

   
def process_file(in_file, out_file):
    with open(in_file, "r", encoding="utf-8") as fin, open(out_file, "w", newline='') as fout:
        rdr = csv.DictReader(fin, delimiter='\t')
        wrtr = csv.writer(fout)
        for row_index, line in enumerate(rdr, start=1):
            ip = line['ipb_address']
            try:          
                net = ((ip_address, ) for ip_address in ipaddress.IPv4Network(ip))
            except ipaddress.AddressValueError:
                print('{} is not valid ip'.format(ip))
            else:
                 wrtr.writerows(net)
    return row_index

if __name__ == '__main__':
    in_file = "fr_block.txt"
    out_file = "fr_block_2.txt"
    num_rows = process_file(in_file=in_file, out_file=out_file)
    print('\n\nTotal rows processed (excluding the header row): {}'.format(num_rows))

[tomthirteen]

Buran, thank you for all your help. I am sorry for the late reply. I am assuming that since you got the script to run all the way to the end, something is wrong with my CPU. This script is not processing all the data to the end. I've been having a lot of problems with my computer. Thanks again. Tom