
"ipaddress" --- IPv4/IPv6 manipulation library
**********************************************

**Source code:** Lib/ipaddress.py

======================================================================

Note: The "ipaddress" module has been included in the standard
  library on a *provisional basis*. Backwards incompatible changes (up
  to and including removal of the package) may occur if deemed
  necessary by the core developers.

"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 *An introduction to the ipaddress module*.

New in version 3.3.


Convenience factory functions
=============================

The "ipaddress" module provides factory functions to conveniently
create IP addresses, networks and interfaces:

ipaddress.ip_address(address)

   Return an "IPv4Address" or "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 "ValueError" is raised if *address* does not represent a
   valid IPv4 or IPv6 address.

   >>> ipaddress.ip_address('192.168.0.1')
   IPv4Address('192.168.0.1')
   >>> ipaddress.ip_address('2001:db8::')
   IPv6Address('2001:db8::')

ipaddress.ip_network(address, strict=True)

   Return an "IPv4Network" or "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 "IPv4Network" or "IPv6Network"
   constructor.  A "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')

ipaddress.ip_interface(address)

   Return an "IPv4Interface" or "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 "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 "IPv4Address" and "IPv6Address" objects share a lot of common
attributes.  Some attributes that are only meaningful for IPv6
addresses are also implemented by "IPv4Address" objects, in order to
make it easier to write code that handles both IP versions correctly.

class class ipaddress.IPv4Address(address)

   Construct an IPv4 address.  An "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 "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')

   version

      The appropriate version number: "4" for IPv4, "6" for IPv6.

   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.

   compressed

   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.

   packed

      The binary representation of this address - a "bytes" object of
      the appropriate length (most significant octet first). This is 4
      bytes for IPv4 and 16 bytes for IPv6.

   is_multicast

      "True" if the address is reserved for multicast use.  See **RFC
      3171** (for IPv4) or **RFC 2373** (for IPv6).

   is_private

      "True" if the address is allocated for private networks.  See
      **RFC 1918** (for IPv4) or **RFC 4193** (for IPv6).

   is_unspecified

      "True" if the address is unspecified.  See **RFC 5735** (for
      IPv4) or **RFC 2373** (for IPv6).

   is_reserved

      "True" if the address is otherwise IETF reserved.

   is_loopback

      "True" if this is a loopback address.  See **RFC 3330** (for
      IPv4) or **RFC 2373** (for IPv6).

   is_link_local

      "True" if the address is reserved for link-local usage.  See
      **RFC 3927**.

class class ipaddress.IPv6Address(address)

   Construct an IPv6 address.  An "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 "bytes" object of length 16, big-
      endian.

   >>> ipaddress.IPv6Address('2001:db8::1000')
   IPv6Address('2001:db8::1000')

   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.

   exploded

   The long form of the address representation, with all leading
   zeroes and groups consisting entirely of zeroes included.

   packed

   version

   max_prefixlen

   is_multicast

   is_private

   is_unspecified

   is_reserved

   is_loopback

   is_link_local

      Refer to the corresponding attribute documentation in
      "IPv4Address"

   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 "is_private" to test if this address is in the space
      of unique local addresses as defined by **RFC 4193**.

   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".

   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".

   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 "str()" and "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 "<stdin>", line 1, in <module>
   ipaddress.AddressValueError: 4294967296 (>= 2**32) is not permitted as an IPv4 address


IP Network definitions
======================

The "IPv4Network" and "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* "/<nbits>" 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 "IPv4Network"
and "IPv6Network", so to avoid duplication they are only documented
for "IPv4Network".

class class ipaddress.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 "bytes" object of length 4, big-
      endian. The interpretation is similar to an integer *address*.

   An "AddressValueError" is raised if *address* is not a valid IPv4
   address.  A "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 "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 "TypeError" if the argument's IP
   version is incompatible to "self"

   version

   max_prefixlen

      Refer to the corresponding attribute documentation in
      "IPv4Address"

   is_multicast

   is_private

   is_unspecified

   is_reserved

   is_loopback

   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

   network_address

      The network address for the network. The network address and the
      prefix length together uniquely define a network.

   broadcast_address

      The broadcast address for the network. Packets sent to the
      broadcast address should be received by every host on the
      network.

   hostmask

      The host mask, as a string.

   with_prefixlen

   compressed

   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.

   with_netmask

      A string representation of the network, with the mask in net
      mask notation.

   with_hostmask

      A string representation of the network, with the mask in host
      mask notation.

   num_addresses

      The total number of addresses in the network.

   prefixlen

      Length of the network prefix, in bits.

   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')]

   overlaps(other)

      "True" if this network is partly or wholly contained in *other*
      or *other* is wholly contained in this network.

   address_exclude(network)

      Computes the network definitions resulting from removing the
      given *network* from this one.  Returns an iterator of network
      objects. Raises "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')]

   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 "<stdin>", line 1, in <module>
          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')]

   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')

   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 class ipaddress.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 "bytes" object of length 16, bit-
      endian. The interpretation is similar to an integer *address*.

   An "AddressValueError" is raised if *address* is not a valid IPv6
   address.  A "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 "ValueError" is raised.  Otherwise, the host bits are
   masked out to determine the appropriate network address.

   version

   max_prefixlen

   is_multicast

   is_private

   is_unspecified

   is_reserved

   is_loopback

   is_link_local

   network_address

   broadcast_address

   hostmask

   with_prefixlen

   compressed

   exploded

   with_netmask

   with_hostmask

   num_addresses

   prefixlen

   hosts()

   overlaps(other)

   address_exclude(network)

   subnets(prefixlen_diff=1, new_prefix=None)

   supernet(prefixlen_diff=1, new_prefix=None)

   compare_networks(other)

      Refer to the corresponding attribute documentation in
      "IPv4Network"

   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 "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 class ipaddress.IPv4Interface(address)

   Construct an IPv4 interface.  The meaning of *address* is as in the
   constructor of "IPv4Network", except that arbitrary host addresses
   are always accepted.

   "IPv4Interface" is a subclass of "IPv4Address", so it inherits all
   the attributes from that class.  In addition, the following
   attributes are available:

   ip

      The address ("IPv4Address") without network information.

      >>> interface = IPv4Interface('192.0.2.5/24')
      >>> interface.ip
      IPv4Address('192.0.2.5')

   network

      The network ("IPv4Network") this interface belongs to.

      >>> interface = IPv4Interface('192.0.2.5/24')
      >>> interface.network
      IPv4Network('192.0.2.0/24')

   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'

   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'

   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 class ipaddress.IPv6Interface(address)

   Construct an IPv6 interface.  The meaning of *address* is as in the
   constructor of "IPv6Network", except that arbitrary host addresses
   are always accepted.

   "IPv6Interface" is a subclass of "IPv6Address", so it inherits all
   the attributes from that class.  In addition, the following
   attributes are available:

   ip

   network

   with_prefixlen

   with_netmask

   with_hostmask

      Refer to the corresponding attribute documentation in
      "IPv4Interface".


Other Module Level Functions
============================

The module also provides the following module level functions:

ipaddress.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 "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'

ipaddress.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 "ValueError" is raised if the integer is negative or
   too large to be an IPv6 IP address.

ipaddress.summarize_address_range(first, last)

   Return an iterator of the summarized network range given the first
   and last IP addresses.  *first* is the first "IPv4Address" or
   "IPv6Address" in the range and *last* is the last "IPv4Address" or
   "IPv6Address" in the range.  A "TypeError" is raised if *first* or
   *last* are not IP addresses or are not of the same version.  A
   "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')]

ipaddress.collapse_addresses(addresses)

   Return an iterator of the collapsed "IPv4Network" or "IPv6Network"
   objects.  *addresses* is an iterator of "IPv4Network" or
   "IPv6Network" objects.  A "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')]

ipaddress.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 "ipaddress" sort these anyway.  If you need to do
   this, you can use this function as the "key" argument to
   "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 exception ipaddress.AddressValueError(ValueError)

   Any value error related to the address.

exception exception ipaddress.NetmaskValueError(ValueError)

   Any value error related to the netmask.
