Parse `ipconfig /all` in Python

ipconfig_parser.py

import subprocess
import collections

Interface = collections.namedtuple('Interface', 'name description subnet_mask ipv4_addresses ipv4_gateway ipv6_addresses ipv6_gateway dhcp_server dns_servers')

def parse_ipconfig():
    """
    Parses results from ipconfig. PowerShell has more structured functions, but
    they don't serialize properly
    (https://stackoverflow.com/questions/69997138/serialization-differences-between-powershells-format-list-and-convertto-json).

    A normal output looks like this:

    Wireless LAN adapter Local Area Connection* 12:

       Autoconfiguration Enabled . . . . : Yes
       DHCP Enabled. . . . . . . . . . . : Yes
       Physical Address. . . . . . . . . : 9C-DA-3E-68-11-37
       Description . . . . . . . . . . . : Microsoft Wi-Fi Direct Virtual Adapter
       Connection-specific DNS Suffix  . : 
       Media State . . . . . . . . . . . : Media disconnected

    Wireless LAN adapter Local Area Connection* 1:

       NetBIOS over Tcpip. . . . . . . . : Enabled
                                           fec0:0:0:ffff::3%1
                                           fec0:0:0:ffff::2%1
       DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
       DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-24-A6-E0-0A-9C-DA-3E-68-11-36
       DHCPv6 IAID . . . . . . . . . . . : 956956711
       Default Gateway . . . . . . . . . : 
       Subnet Mask . . . . . . . . . . . : 255.255.255.0
       IPv4 Address. . . . . . . . . . . : 192.168.56.1(Preferred) 
       Link-local IPv6 Address . . . . . : fe80::d83f:9609:86ff:2b57%23(Preferred) 
       Autoconfiguration Enabled . . . . : Yes
       DHCP Enabled. . . . . . . . . . . : No
       Physical Address. . . . . . . . . : 0A-00-27-00-00-17
       Description . . . . . . . . . . . : VirtualBox Host-Only Ethernet Adapter
       Connection-specific DNS Suffix  . : 
    """
    result = subprocess.run(["ipconfig", "/all"], capture_output=True, text=True)
    assert result.returncode == 0
    interfaces = []
    lines = result.stdout.strip().split('\n')
    while lines:
        # Parse an interface section.
        interface_name = lines.pop(0)
        # Ignore the empty line after the interface name.
        assert not lines.pop(0)

        # Parse section line by line.
        attributes = {'Name': interface_name}
        last_attribute_name = None
        while lines:
            line = lines.pop(0)
            # Sections are separated by empty lines.
            if not line:
                break

            # Fields may encode multiple values in separate, indented lines:
            #
            #    Default Gateway . . . . . . . . . : fe80::1%8
            #                                        192.168.2.1
            if line.startswith('    '):
                # We are in a continuation value, assume the name is the same
                # as before.
                value = line
                attribute_name = last_attribute_name
            else:
                left, value = line.split(' : ')
                attribute_name = left.strip('. ')

            # IP addresses are often formatted as "192.168.56.1(Preferred)"
            # or "192.168.56.1(Deprecated)". Remove those labels.
            value = value.replace('(Preferred)', '').replace('(Deprecated)', '').strip()

            if not value:
                # Skip empty values. They'll be converted to None's at the end.
                continue

            if attribute_name == last_attribute_name:
                # Some sections may contain duplicated fields, or fields spanning
                # multiple lines. Put the values in a list.
                if not isinstance(attributes[last_attribute_name], list):
                    attributes[last_attribute_name] = [attributes[last_attribute_name]]
                attributes[last_attribute_name].append(value)
            else:
                if attribute_name in ('Default Gateway', 'IPv4 Address', 'IPv6 Address', 'DNS Servers'):
                    # Fields that should always be lists, even if just one value
                    # is provided.
                    value = [value]
                attributes[attribute_name] = value
                last_attribute_name = attribute_name

        field_name_mapping = {'name': 'Name', 'description': 'Description', 'subnet_mask': 'Subnet Mask', 'ipv4_addresses': 'IPv4 Address', 'ipv6_addresses': 'IPv6 Address', 'dhcp_server': 'DHCP Server', 'dns_servers': 'DNS Servers'}

        # Gateways are given with IPv4 and IPv6 mixed, and we have to fix that.
        ipv4_gateway = ''
        ipv6_gateway = ''
        for gateway in attributes.get('Default Gateway', []):
            if ':' in gateway:
                ipv6_gateway = gateway
            else:
                ipv4_gateway = gateway

        interface = Interface(ipv4_gateway=ipv4_gateway, ipv6_gateway=ipv6_gateway, **{n: attributes.get(m) for n, m in field_name_mapping.items()})
        interfaces.append(interface)

    return interfaces

if __name__ == '__main__':
    from pprint import pprint
    pprint(parse_ipconfig())
    # Example interface:
    # Interface(name='Ethernet adapter VirtualBox Host-Only Network:', description='VirtualBox Host-Only Ethernet Adapter', subnet_mask='255.255.255.0', ipv4_addresses=['192.168.56.1'], ipv4_gateway='', ipv6_addresses=None, ipv6_gateway='', dhcp_server=None, dns_servers=['fec0:0:0:ffff::1%1', 'fec0:0:0:ffff::2%1', 'fec0:0:0:ffff::3%1'])