cidr_summarize.py

#!/usr/bin/env python
# GistID: 3285baf647fd1403ce18
import sys
from netaddr import IPNetwork, cidr_merge, AddrFormatError

CF_ANYCAST_NETS = []
lines = []
if len(sys.argv) > 1:
    with open(sys.argv[1]) as f:
        for line in f.readlines():
            lines.append(line)
else:
    for line in sys.stdin.readlines():
        lines.append(line)

for line in lines:
    try:
        CF_ANYCAST_NETS.append(IPNetwork(line))
    except AddrFormatError:
        pass

for net in cidr_merge(CF_ANYCAST_NETS):
    print net