Setting the file. One moment.
Subchapter 184.2
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ipaddress package, with passed to constructors where available.strict=True/128 for IPv6 and /32 for IPv4.Use the convenience factory functions in ipaddress (opens in a new tab).
The following ipaddress.ip_address(textAddress) examples parse text into IPv4Address and IPv6Address objects, respectively:
ipaddress.ip_address('192.168.0.1')
ipaddress.ip_address('2001:db8::')The following ipaddress.ip_network(address, strict=True) example parses a subnet string and returns an IPv4Network or IPv6Network object, failing on invalid input:
ipaddress.ip_network('192.168.0.0/28', strict=True)The following strict-mode call fails (correctly) with ValueError: 192.168.0.1/30 has host bits set. Ask the user to fix such errors; do not guess corrections:
ipaddress.ip_network('192.168.0.1/30', strict=True)Use the strict-form parser ipaddress.ip_network(address, strict=True) (opens in a new tab).
Use a Python dictionary to track subnets and their associated geolocation properties. IPv4Network, IPv6Network, IPv4Address, and IPv6Address are all hashable and can be used as dictionary keys.
The SKILL.md references is_private for detecting non-public ranges. Use the network’s properties:
import ipaddress
def is_non_public(network):
"""Check if a network is non-public (private, loopback, link-local, multicast, or reserved).
Note: In Python < 3.11, is_private may incorrectly flag some ranges
(e.g., 100.64.0.0/10 CGNAT space). Use is_global as the primary check
when available, with fallbacks for edge cases.
"""
addr = network.network_address
return (
network.is_private
or network.is_loopback
or network.is_link_local
or network.is_multicast
or network.is_reserved
or not network.is_global # catches most non-routable space
)Caution with is_private on Python < 3.11: The 100.64.0.0/10 (Carrier-Grade NAT) range returns is_private=True but is_global=False in older Python versions. Since CGNAT space is not globally routable, flagging it as non-public is correct for RFC 8805 purposes.
Read the valid ISO 2-letter country codes from assets/iso3166-1.json, specifically the alpha_2 attribute:
import json
with open('assets/iso3166-1.json') as f:
data = json.load(f)
valid_countries = {c['alpha_2'] for c in data['3166-1']}Read the valid region codes from assets/iso3166-2.json, specifically the code attribute. The top-level key is 3166-2 (matching the iso3166-1 pattern):
import json
with open('assets/iso3166-2.json') as f:
data = json.load(f)
valid_regions = {r['code'] for r in data['3166-2']}