This takes https://www.blocklist.de/en/export.html IPs and puts them in ipsets that can be used for firewalling with netfilter/iptables

blocklist.service

[Unit]
Description=update ipsets from blocklist.de
Wants=network-online.target
After=network-online.target
ConditionACPower=true

[Service]
Type=oneshot

# Lower CPU and I/O priority.
Nice=19
CPUSchedulingPolicy=batch
IOSchedulingClass=best-effort
IOSchedulingPriority=7
IOWeight=100

Restart=no
LogRateLimitIntervalSec=0

ExecStart=systemd-inhibit --who="ipset" --why="Prevent interrupting our ipset update" /etc/ipset-delta.py

blocklist.timer

[Unit]
Description=Run blocklist ipset update

[Timer]
OnBootSec=30min
OnUnitActiveSec=30min
Persistent=true

[Install]
WantedBy=timers.target

ipset-delta.py

#!/usr/bin/python3
import shutil
import requests
import os
import ipaddress
from pathlib import Path

oldFileName = '/etc/blocklist.all.txt'
newFileName = '/etc/blocklist.all.txt.new'

try:
    shutil.move(newFileName, oldFileName)
except:
    pass
url = 'https://lists.blocklist.de/lists/all.txt'
filename = Path(newFileName)
filename.touch(exist_ok=True)
#response = requests.get(url, headers={'User-Agent': 'Mozilla'})
with requests.get(url, headers={'User-Agent': 'Mozilla'}) as r:
    r.encoding = r.apparent_encoding
    with open(filename, 'wb') as f:
        f.write(r.content)
    f.close()

oldFile = open(oldFileName, 'r')
newFile = open(newFileName, 'r')
oldSet = set()
for line in oldFile:
    try:
        ipaddress.ip_address(line.rstrip())
    except:
        continue
    oldSet.add(line.rstrip())
oldFile.close()
newSet = set()
for line in newFile:
    try:
        ipaddress.ip_address(line.rstrip())
    except:
        continue
    newSet.add(line.rstrip())
newFile.close()
unchanged = oldSet & newSet
todelete = oldSet - newSet
additions = newSet - oldSet
for item in todelete:
    print("removing: \"%s\"" % item)
    try:
        ipaddress.IPv6Address(item)
        os.system("/usr/sbin/ipset del blocklist6 %s" % item)
    except:
        os.system("/usr/sbin/ipset del blocklist %s" % item)
for item in additions:
    print("need to add: \"%s\"" % item)
    try:
        ipaddress.IPv6Address(item)
        os.system("/usr/sbin/ipset add blocklist6 %s" % item)
    except:
        os.system("/usr/sbin/ipset add blocklist %s" % item)
os.system("ipset save > /etc/ipsets.conf")

ipset-init4.py

#!/usr/bin/python3
import shutil
import requests
import os
import subprocess
from io import StringIO
import ipaddress

result = subprocess.run(['/usr/sbin/ipset', 'list', 'blocklist'], stdout=subprocess.PIPE, check=True)
oldSet = set()
buf=StringIO(result.stdout.decode('utf-8'))
for line in buf.read().split("\n"):
    try:
        ipaddress.IPv4Address(line.rstrip())
    except:
        continue
    #print("line: \"%s\"" % line)
    oldSet.add(line.rstrip())

newFileName = '/etc/blocklist.all.txt'

newFile = open(newFileName, 'r')
newSet = set()
for line in newFile:
    try:
        ipaddress.IPv4Address(line.rstrip())
    except:
        continue
    newSet.add(line.rstrip())
newFile.close()


unchanged = oldSet & newSet
todelete = oldSet - newSet
additions = newSet - oldSet
for item in todelete:
    print("removing: \"%s\"" % item)
    os.system("/usr/sbin/ipset del blocklist %s" % item)
for item in additions:
    print("adding: \"%s\"" % item)
    os.system("/usr/sbin/ipset add blocklist %s" % item)
os.system("ipset save > /etc/ipsets.conf")

ipset-init6.py

#!/usr/bin/python3
import shutil
import requests
import os
import subprocess
from io import StringIO
import ipaddress

result = subprocess.run(['/usr/sbin/ipset', 'list', 'blocklist6'], stdout=subprocess.PIPE, check=True)
oldSet = set()
buf=StringIO(result.stdout.decode('utf-8'))
for line in buf.read().split("\n"):
    try:
        ipaddress.IPv6Address(line.rstrip())
    except:
        continue
    #print("line: \"%s\"" % line)
    oldSet.add(line.rstrip())

newFileName = '/etc/blocklist.all.txt'

newFile = open(newFileName, 'r')
newSet = set()
for line in newFile:
    try:
        ipaddress.IPv6Address(line.rstrip())
    except:
        continue
    newSet.add(line.rstrip())
newFile.close()


unchanged = oldSet & newSet
todelete = oldSet - newSet
additions = newSet - oldSet
for item in todelete:
    print("removing: \"%s\"" % item)
    os.system("/usr/sbin/ipset del blocklist6 %s" % item)
for item in additions:
    print("adding: \"%s\"" % item)
    os.system("/usr/sbin/ipset add blocklist6 %s" % item)
os.system("ipset save > /etc/ipsets.conf")

ipset-persistent.service

[Unit]
Description=ipset persistancy service
DefaultDependencies=no
Requires=netfilter-persistent.service
Before=network.target
Before=netfilter-persistent.service
ConditionFileNotEmpty=/etc/ipsets.conf

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/sbin/ipset restore -f -! /etc/ipsets.conf

# save on service stop, system shutdown etc.
ExecStop=/usr/sbin/ipset save blacklist -f /etc/ipsets.conf

[Install]
WantedBy=multi-user.target

RequiredBy=netfilter-persistent.service