:mod:`ipaddress` --- IPv4/IPv6 manipulation library =================================================== .. module:: ipaddress :synopsis: IPv4/IPv6 manipulation library. .. moduleauthor:: Peter Moody **Source code:** :source:`Lib/ipaddress.py` -------------- .. note:: The ``ipaddress`` module has been included in the standard library on a :term:`provisional basis `. Backwards incompatible changes (up to and including removal of the package) may occur if deemed necessary by the core developers. :mod:`ipaddress` provides the capabilities to create, manipulate and operate on IPv4 and IPv6 addresses and networks. The functions and classes in this module make it straightforward to handle various tasks related to IP addresses, including checking whether or not two hosts are on the same subnet, iterating over all hosts in a particular subnet, checking whether or not a string represents a valid IP address or network definition, and so on. This is the full module API reference - for an overview and introduction, see :ref:`ipaddress-howto`. .. versionadded:: 3.3 Convenience factory functions ----------------------------- The :mod:`ipaddress` module provides factory functions to conveniently create IP addresses, networks and interfaces: .. function:: ip_address(address) Return an :class:`IPv4Address` or :class:`IPv6Address` object depending on the IP address passed as argument. Either IPv4 or IPv6 addresses may be supplied; integers less than 2**32 will be considered to be IPv4 by default. A :exc:`ValueError` is raised if *address* does not represent a valid IPv4 or IPv6 address. .. testsetup:: >>> import ipaddress >>> from ipaddress import (ip_network, IPv4Address, IPv4Interface, ... IPv4Network) :: >>> ipaddress.ip_address('192.168.0.1') IPv4Address('192.168.0.1') >>> ipaddress.ip_address('2001:db8::') IPv6Address('2001:db8::') .. function:: ip_network(address, strict=True) Return an :class:`IPv4Network` or :class:`IPv6Network` object depending on the IP address passed as argument. *address* is a string or integer representing the IP network. Either IPv4 or IPv6 networks may be supplied; integers less than 2**32 will be considered to be IPv4 by default. *strict* is passed to :class:`IPv4Network` or :class:`IPv6Network` constructor. A :exc:`ValueError` is raised if *address* does not represent a valid IPv4 or IPv6 address, or if the network has host bits set. >>> ipaddress.ip_network('192.168.0.0/28') IPv4Network('192.168.0.0/28') .. function:: ip_interface(address) Return an :class:`IPv4Interface` or :class:`IPv6Interface` object depending on the IP address passed as argument. *address* is a string or integer representing the IP address. Either IPv4 or IPv6 addresses may be supplied; integers less than 2**32 will be considered to be IPv4 by default. A :exc:`ValueError` is raised if *address* does not represent a valid IPv4 or IPv6 address. One downside of these convenience functions is that the need to handle both IPv4 and IPv6 formats means that error messages provide minimal information on the precise error, as the functions don't know whether the IPv4 or IPv6 format was intended. More detailed error reporting can be obtained by calling the appropriate version specific class constructors directly. IP Addresses ------------ Address objects ^^^^^^^^^^^^^^^ The :class:`IPv4Address` and :class:`IPv6Address` objects share a lot of common attributes. Some attributes that are only meaningful for IPv6 addresses are also implemented by :class:`IPv4Address` objects, in order to make it easier to write code that handles both IP versions correctly. .. class:: IPv4Address(address) Construct an IPv4 address. An :exc:`AddressValueError` is raised if *address* is not a valid IPv4 address. The following constitutes a valid IPv4 address: 1. A string in decimal-dot notation, consisting of four decimal integers in the inclusive range 0-255, separated by dots (e.g. ``192.168.0.1``). Each integer represents an octet (byte) in the address. Leading zeroes are tolerated only for values less then 8 (as there is no ambiguity between the decimal and octal interpretations of such strings). 2. An integer that fits into 32 bits. 3. An integer packed into a :class:`bytes` object of length 4 (most significant octet first). >>> ipaddress.IPv4Address('192.168.0.1') IPv4Address('192.168.0.1') >>> ipaddress.IPv4Address(3232235521) IPv4Address('192.168.0.1') >>> ipaddress.IPv4Address(b'\xC0\xA8\x00\x01') IPv4Address('192.168.0.1') .. attribute:: version The appropriate version number: ``4`` for IPv4, ``6`` for IPv6. .. attribute:: max_prefixlen The total number of bits in the address representation for this version: ``32`` for IPv4, ``128`` for IPv6. The prefix defines the number of leading bits in an address that are compared to determine whether or not an address is part of a network. .. attribute:: compressed .. attribute:: exploded The string representation in dotted decimal notation. Leading zeroes are never included in the representation. As IPv4 does not define a shorthand notation for addresses with octets set to zero, these two attributes are always the same as ``str(addr)`` for IPv4 addresses. Exposing these attributes makes it easier to write display code that can handle both IPv4 and IPv6 addresses. .. attribute:: packed The binary representation of this address - a :class:`bytes` object of the appropriate length (most significant octet first). This is 4 bytes for IPv4 and 16 bytes for IPv6. .. attribute:: is_multicast ``True`` if the address is reserved for multicast use. See :RFC:`3171` (for IPv4) or :RFC:`2373` (for IPv6). .. attribute:: is_private ``True`` if the address is allocated for private networks. See iana-ipv4-special-registry (for IPv4) or iana-ipv6-special-registry (for IPv6). .. attribute:: is_global ``True`` if the address is allocated for public networks. See iana-ipv4-special-registry (for IPv4) or iana-ipv6-special-registry (for IPv6). .. versionadded:: 3.4 .. attribute:: is_unspecified ``True`` if the address is unspecified. See :RFC:`5375` (for IPv4) or :RFC:`2373` (for IPv6). .. attribute:: is_reserved ``True`` if the address is otherwise IETF reserved. .. attribute:: is_loopback ``True`` if this is a loopback address. See :RFC:`3330` (for IPv4) or :RFC:`2373` (for IPv6). .. attribute:: is_link_local ``True`` if the address is reserved for link-local usage. See :RFC:`3927`. .. class:: IPv6Address(address) Construct an IPv6 address. An :exc:`AddressValueError` is raised if *address* is not a valid IPv6 address. The following constitutes a valid IPv6 address: 1. A string consisting of eight groups of four hexadecimal digits, each group representing 16 bits. The groups are separated by colons. This describes an *exploded* (longhand) notation. The string can also be *compressed* (shorthand notation) by various means. See :RFC:`4291` for details. For example, ``"0000:0000:0000:0000:0000:0abc:0007:0def"`` can be compressed to ``"::abc:7:def"``. 2. An integer that fits into 128 bits. 3. An integer packed into a :class:`bytes` object of length 16, big-endian. >>> ipaddress.IPv6Address('2001:db8::1000') IPv6Address('2001:db8::1000') .. attribute:: compressed The short form of the address representation, with leading zeroes in groups omitted and the longest sequence of groups consisting entirely of zeroes collapsed to a single empty group. This is also the value returned by ``str(addr)`` for IPv6 addresses. .. attribute:: exploded The long form of the address representation, with all leading zeroes and groups consisting entirely of zeroes included. .. attribute:: packed .. attribute:: version .. attribute:: max_prefixlen .. attribute:: is_multicast .. attribute:: is_private .. attribute:: is_unspecified .. attribute:: is_reserved .. attribute:: is_loopback .. attribute:: is_link_local Refer to the corresponding attribute documentation in :class:`IPv4Address` .. attribute:: is_site_local ``True`` if the address is reserved for site-local usage. Note that the site-local address space has been deprecated by :RFC:`3879`. Use :attr:`~IPv4Address.is_private` to test if this address is in the space of unique local addresses as defined by :RFC:`4193`. .. attribute:: ipv4_mapped For addresses that appear to be IPv4 mapped addresses (starting with ``::FFFF/96``), this property will report the embedded IPv4 address. For any other address, this property will be ``None``. .. attribute:: sixtofour For addresses that appear to be 6to4 addresses (starting with ``2002::/16``) as defined by :RFC:`3056`, this property will report the embedded IPv4 address. For any other address, this property will be ``None``. .. attribute:: teredo For addresses that appear to be Teredo addresses (starting with ``2001::/32``) as defined by :RFC:`4380`, this property will report the embedded ``(server, client)`` IP address pair. For any other address, this property will be ``None``. Conversion to Strings and Integers ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ To interoperate with networking interfaces such as the socket module, addresses must be converted to strings or integers. This is handled using the :func:`str` and :func:`int` builtin functions:: >>> str(ipaddress.IPv4Address('192.168.0.1')) '192.168.0.1' >>> int(ipaddress.IPv4Address('192.168.0.1')) 3232235521 >>> str(ipaddress.IPv6Address('::1')) '::1' >>> int(ipaddress.IPv6Address('::1')) 1 Operators ^^^^^^^^^ Address objects support some operators. Unless stated otherwise, operators can only be applied between compatible objects (i.e. IPv4 with IPv4, IPv6 with IPv6). Comparison operators """""""""""""""""""" Address objects can be compared with the usual set of comparison operators. Some examples:: >>> IPv4Address('127.0.0.2') > IPv4Address('127.0.0.1') True >>> IPv4Address('127.0.0.2') == IPv4Address('127.0.0.1') False >>> IPv4Address('127.0.0.2') != IPv4Address('127.0.0.1') True Arithmetic operators """""""""""""""""""" Integers can be added to or subtracted from address objects. Some examples:: >>> IPv4Address('127.0.0.2') + 3 IPv4Address('127.0.0.5') >>> IPv4Address('127.0.0.2') - 3 IPv4Address('126.255.255.255') >>> IPv4Address('255.255.255.255') + 1 Traceback (most recent call last): File "", line 1, in ipaddress.AddressValueError: 4294967296 (>= 2**32) is not permitted as an IPv4 address IP Network definitions ---------------------- The :class:`IPv4Network` and :class:`IPv6Network` objects provide a mechanism for defining and inspecting IP network definitions. A network definition consists of a *mask* and a *network address*, and as such defines a range of IP addresses that equal the network address when masked (binary AND) with the mask. For example, a network definition with the mask ``255.255.255.0`` and the network address ``192.168.1.0`` consists of IP addresses in the inclusive range ``192.168.1.0`` to ``192.168.1.255``. Prefix, net mask and host mask ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ There are several equivalent ways to specify IP network masks. A *prefix* ``/`` is a notation that denotes how many high-order bits are set in the network mask. A *net mask* is an IP address with some number of high-order bits set. Thus the prefix ``/24`` is equivalent to the net mask ``255.255.255.0`` in IPv4, or ``ffff:ff00::`` in IPv6. In addition, a *host mask* is the logical inverse of a *net mask*, and is sometimes used (for example in Cisco access control lists) to denote a network mask. The host mask equivalent to ``/24`` in IPv4 is ``0.0.0.255``. Network objects ^^^^^^^^^^^^^^^ All attributes implemented by address objects are implemented by network objects as well. In addition, network objects implement additional attributes. All of these are common between :class:`IPv4Network` and :class:`IPv6Network`, so to avoid duplication they are only documented for :class:`IPv4Network`. .. class:: IPv4Network(address, strict=True) Construct an IPv4 network definition. *address* can be one of the following: 1. A string consisting of an IP address and an optional mask, separated by a slash (``/``). The IP address is the network address, and the mask can be either a single number, which means it's a *prefix*, or a string representation of an IPv4 address. If it's the latter, the mask is interpreted as a *net mask* if it starts with a non-zero field, or as a *host mask* if it starts with a zero field. If no mask is provided, it's considered to be ``/32``. For example, the following *address* specifications are equivalent: ``192.168.1.0/24``, ``192.168.1.0/255.255.255.0`` and ``192.168.1.0/0.0.0.255``. 2. An integer that fits into 32 bits. This is equivalent to a single-address network, with the network address being *address* and the mask being ``/32``. 3. An integer packed into a :class:`bytes` object of length 4, big-endian. The interpretation is similar to an integer *address*. An :exc:`AddressValueError` is raised if *address* is not a valid IPv4 address. A :exc:`NetmaskValueError` is raised if the mask is not valid for an IPv4 address. If *strict* is ``True`` and host bits are set in the supplied address, then :exc:`ValueError` is raised. Otherwise, the host bits are masked out to determine the appropriate network address. Unless stated otherwise, all network methods accepting other network/address objects will raise :exc:`TypeError` if the argument's IP version is incompatible to ``self`` .. attribute:: version .. attribute:: max_prefixlen Refer to the corresponding attribute documentation in :class:`IPv4Address` .. attribute:: is_multicast .. attribute:: is_private .. attribute:: is_unspecified .. attribute:: is_reserved .. attribute:: is_loopback .. attribute:: is_link_local These attributes are true for the network as a whole if they are true for both the network address and the broadcast address .. attribute:: network_address The network address for the network. The network address and the prefix length together uniquely define a network. .. attribute:: broadcast_address The broadcast address for the network. Packets sent to the broadcast address should be received by every host on the network. .. attribute:: host mask The host mask, as a string. .. attribute:: with_prefixlen .. attribute:: compressed .. attribute:: exploded A string representation of the network, with the mask in prefix notation. ``with_prefixlen`` and ``compressed`` are always the same as ``str(network)``. ``exploded`` uses the exploded form the network address. .. attribute:: with_netmask A string representation of the network, with the mask in net mask notation. .. attribute:: with_hostmask A string representation of the network, with the mask in host mask notation. .. attribute:: num_addresses The total number of addresses in the network. .. attribute:: prefixlen Length of the network prefix, in bits. .. method:: hosts() Returns an iterator over the usable hosts in the network. The usable hosts are all the IP addresses that belong to the network, except the network address itself and the network broadcast address. >>> list(ip_network('192.0.2.0/29').hosts()) #doctest: +NORMALIZE_WHITESPACE [IPv4Address('192.0.2.1'), IPv4Address('192.0.2.2'), IPv4Address('192.0.2.3'), IPv4Address('192.0.2.4'), IPv4Address('192.0.2.5'), IPv4Address('192.0.2.6')] .. method:: overlaps(other) ``True`` if this network is partly or wholly contained in *other* or *other* is wholly contained in this network. .. method:: address_exclude(network) Computes the network definitions resulting from removing the given *network* from this one. Returns an iterator of network objects. Raises :exc:`ValueError` if *network* is not completely contained in this network. >>> n1 = ip_network('192.0.2.0/28') >>> n2 = ip_network('192.0.2.1/32') >>> list(n1.address_exclude(n2)) #doctest: +NORMALIZE_WHITESPACE [IPv4Network('192.0.2.8/29'), IPv4Network('192.0.2.4/30'), IPv4Network('192.0.2.2/31'), IPv4Network('192.0.2.0/32')] .. method:: subnets(prefixlen_diff=1, new_prefix=None) The subnets that join to make the current network definition, depending on the argument values. *prefixlen_diff* is the amount our prefix length should be increased by. *new_prefix* is the desired new prefix of the subnets; it must be larger than our prefix. One and only one of *prefixlen_diff* and *new_prefix* must be set. Returns an iterator of network objects. >>> list(ip_network('192.0.2.0/24').subnets()) [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/25')] >>> list(ip_network('192.0.2.0/24').subnets(prefixlen_diff=2)) #doctest: +NORMALIZE_WHITESPACE [IPv4Network('192.0.2.0/26'), IPv4Network('192.0.2.64/26'), IPv4Network('192.0.2.128/26'), IPv4Network('192.0.2.192/26')] >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=26)) #doctest: +NORMALIZE_WHITESPACE [IPv4Network('192.0.2.0/26'), IPv4Network('192.0.2.64/26'), IPv4Network('192.0.2.128/26'), IPv4Network('192.0.2.192/26')] >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=23)) Traceback (most recent call last): File "", line 1, in raise ValueError('new prefix must be longer') ValueError: new prefix must be longer >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=25)) [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/25')] .. method:: supernet(prefixlen_diff=1, new_prefix=None) The supernet containing this network definition, depending on the argument values. *prefixlen_diff* is the amount our prefix length should be decreased by. *new_prefix* is the desired new prefix of the supernet; it must be smaller than our prefix. One and only one of *prefixlen_diff* and *new_prefix* must be set. Returns a single network object. >>> ip_network('192.0.2.0/24').supernet() IPv4Network('192.0.2.0/23') >>> ip_network('192.0.2.0/24').supernet(prefixlen_diff=2) IPv4Network('192.0.0.0/22') >>> ip_network('192.0.2.0/24').supernet(new_prefix=20) IPv4Network('192.0.0.0/20') .. method:: compare_networks(other) Compare this network to *other*. In this comparison only the network addresses are considered; host bits aren't. Returns either ``-1``, ``0`` or ``1``. >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.2/32')) -1 >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.0/32')) 1 >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.1/32')) 0 .. class:: IPv6Network(address, strict=True) Construct an IPv6 network definition. *address* can be one of the following: 1. A string consisting of an IP address and an optional mask, separated by a slash (``/``). The IP address is the network address, and the mask can be either a single number, which means it's a *prefix*, or a string representation of an IPv6 address. If it's the latter, the mask is interpreted as a *net mask*. If no mask is provided, it's considered to be ``/128``. For example, the following *address* specifications are equivalent: ``2001:db00::0/24`` and ``2001:db00::0/ffff:ff00::``. 2. An integer that fits into 128 bits. This is equivalent to a single-address network, with the network address being *address* and the mask being ``/128``. 3. An integer packed into a :class:`bytes` object of length 16, bit-endian. The interpretation is similar to an integer *address*. An :exc:`AddressValueError` is raised if *address* is not a valid IPv6 address. A :exc:`NetmaskValueError` is raised if the mask is not valid for an IPv6 address. If *strict* is ``True`` and host bits are set in the supplied address, then :exc:`ValueError` is raised. Otherwise, the host bits are masked out to determine the appropriate network address. .. attribute:: version .. attribute:: max_prefixlen .. attribute:: is_multicast .. attribute:: is_private .. attribute:: is_unspecified .. attribute:: is_reserved .. attribute:: is_loopback .. attribute:: is_link_local .. attribute:: network_address .. attribute:: broadcast_address .. attribute:: host mask .. attribute:: with_prefixlen .. attribute:: compressed .. attribute:: exploded .. attribute:: with_netmask .. attribute:: with_hostmask .. attribute:: num_addresses .. attribute:: prefixlen .. method:: hosts() .. method:: overlaps(other) .. method:: address_exclude(network) .. method:: subnets(prefixlen_diff=1, new_prefix=None) .. method:: supernet(prefixlen_diff=1, new_prefix=None) .. method:: compare_networks(other) Refer to the corresponding attribute documentation in :class:`IPv4Network` .. attribute:: is_site_local These attribute is true for the network as a whole if it is true for both the network address and the broadcast address Operators ^^^^^^^^^ Network objects support some operators. Unless stated otherwise, operators can only be applied between compatible objects (i.e. IPv4 with IPv4, IPv6 with IPv6). Logical operators """"""""""""""""" Network objects can be compared with the usual set of logical operators, similarly to address objects. Iteration """"""""" Network objects can be iterated to list all the addresses belonging to the network. For iteration, *all* hosts are returned, including unusable hosts (for usable hosts, use the :meth:`~IPv4Network.hosts` method). An example:: >>> for addr in IPv4Network('192.0.2.0/28'): ... addr ... IPv4Address('192.0.2.0') IPv4Address('192.0.2.1') IPv4Address('192.0.2.2') IPv4Address('192.0.2.3') IPv4Address('192.0.2.4') IPv4Address('192.0.2.5') IPv4Address('192.0.2.6') IPv4Address('192.0.2.7') IPv4Address('192.0.2.8') IPv4Address('192.0.2.9') IPv4Address('192.0.2.10') IPv4Address('192.0.2.11') IPv4Address('192.0.2.12') IPv4Address('192.0.2.13') IPv4Address('192.0.2.14') IPv4Address('192.0.2.15') Networks as containers of addresses """"""""""""""""""""""""""""""""""" Network objects can act as containers of addresses. Some examples:: >>> IPv4Network('192.0.2.0/28')[0] IPv4Address('192.0.2.0') >>> IPv4Network('192.0.2.0/28')[15] IPv4Address('192.0.2.15') >>> IPv4Address('192.0.2.6') in IPv4Network('192.0.2.0/28') True >>> IPv4Address('192.0.3.6') in IPv4Network('192.0.2.0/28') False Interface objects ----------------- .. class:: IPv4Interface(address) Construct an IPv4 interface. The meaning of *address* is as in the constructor of :class:`IPv4Network`, except that arbitrary host addresses are always accepted. :class:`IPv4Interface` is a subclass of :class:`IPv4Address`, so it inherits all the attributes from that class. In addition, the following attributes are available: .. attribute:: ip The address (:class:`IPv4Address`) without network information. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.ip IPv4Address('192.0.2.5') .. attribute:: network The network (:class:`IPv4Network`) this interface belongs to. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.network IPv4Network('192.0.2.0/24') .. attribute:: with_prefixlen A string representation of the interface with the mask in prefix notation. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.with_prefixlen '192.0.2.5/24' .. attribute:: with_netmask A string representation of the interface with the network as a net mask. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.with_netmask '192.0.2.5/255.255.255.0' .. attribute:: with_hostmask A string representation of the interface with the network as a host mask. >>> interface = IPv4Interface('192.0.2.5/24') >>> interface.with_hostmask '192.0.2.5/0.0.0.255' .. class:: IPv6Interface(address) Construct an IPv6 interface. The meaning of *address* is as in the constructor of :class:`IPv6Network`, except that arbitrary host addresses are always accepted. :class:`IPv6Interface` is a subclass of :class:`IPv6Address`, so it inherits all the attributes from that class. In addition, the following attributes are available: .. attribute:: ip .. attribute:: network .. attribute:: with_prefixlen .. attribute:: with_netmask .. attribute:: with_hostmask Refer to the corresponding attribute documentation in :class:`IPv4Interface`. Other Module Level Functions ---------------------------- The module also provides the following module level functions: .. function:: v4_int_to_packed(address) Represent an address as 4 packed bytes in network (big-endian) order. *address* is an integer representation of an IPv4 IP address. A :exc:`ValueError` is raised if the integer is negative or too large to be an IPv4 IP address. >>> ipaddress.ip_address(3221225985) IPv4Address('192.0.2.1') >>> ipaddress.v4_int_to_packed(3221225985) b'\xc0\x00\x02\x01' .. function:: v6_int_to_packed(address) Represent an address as 16 packed bytes in network (big-endian) order. *address* is an integer representation of an IPv6 IP address. A :exc:`ValueError` is raised if the integer is negative or too large to be an IPv6 IP address. .. function:: summarize_address_range(first, last) Return an iterator of the summarized network range given the first and last IP addresses. *first* is the first :class:`IPv4Address` or :class:`IPv6Address` in the range and *last* is the last :class:`IPv4Address` or :class:`IPv6Address` in the range. A :exc:`TypeError` is raised if *first* or *last* are not IP addresses or are not of the same version. A :exc:`ValueError` is raised if *last* is not greater than *first* or if *first* address version is not 4 or 6. >>> [ipaddr for ipaddr in ipaddress.summarize_address_range( ... ipaddress.IPv4Address('192.0.2.0'), ... ipaddress.IPv4Address('192.0.2.130'))] [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/31'), IPv4Network('192.0.2.130/32')] .. function:: collapse_addresses(addresses) Return an iterator of the collapsed :class:`IPv4Network` or :class:`IPv6Network` objects. *addresses* is an iterator of :class:`IPv4Network` or :class:`IPv6Network` objects. A :exc:`TypeError` is raised if *addresses* contains mixed version objects. >>> [ipaddr for ipaddr in ... ipaddress.collapse_addresses([ipaddress.IPv4Network('192.0.2.0/25'), ... ipaddress.IPv4Network('192.0.2.128/25')])] [IPv4Network('192.0.2.0/24')] .. function:: get_mixed_type_key(obj) Return a key suitable for sorting between networks and addresses. Address and Network objects are not sortable by default; they're fundamentally different, so the expression:: IPv4Address('192.0.2.0') <= IPv4Network('192.0.2.0/24') doesn't make sense. There are some times however, where you may wish to have :mod:`ipaddress` sort these anyway. If you need to do this, you can use this function as the ``key`` argument to :func:`sorted()`. *obj* is either a network or address object. Custom Exceptions ----------------- To support more specific error reporting from class constructors, the module defines the following exceptions: .. exception:: AddressValueError(ValueError) Any value error related to the address. .. exception:: NetmaskValueError(ValueError) Any value error related to the netmask.