from os.path import split
import dns.resolver
import ipaddress


def parse_spf_parts(part):
    if part.startswith('ip4:'):
        return [part[4:]]
    elif part.startswith('ip6:'):
        return [part[4:]]
    elif part.startswith('include'):
        return get_spf_record(part[8:])
    elif part.startswith('a'):
        addresses = []
        for address in dns.resolver.resolve_name(part[2:]).addresses():
            addresses.append(address)
        return addresses
    else:
        return []


def get_spf_record(domain_name):
    spf_record = ''
    servers = []
    txt_records = dns.resolver.resolve(domain_name, 'TXT')
    for record in txt_records:
        if record.to_text().find('v=spf1') > 0:
            spf_record = record.to_text()
    parts = spf_record.split()
    for part in parts:
        servers += (parse_spf_parts(part))
    return servers


spf_servers = get_spf_record('trivago.com')
print(spf_servers)