"ipaddress" --- IPv4/IPv6 操作函式庫
************************************

**原始碼：**Lib/ipaddress.py

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

"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 ipaddress 模組介紹.

在 3.3 版被加入.


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.
Address objects are *hashable*, so they can be used as keys in
dictionaries.

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 not tolerated to prevent confusion
      with octal notation.

   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')

   在 3.8 版的變更: Leading zeros are tolerated, even in ambiguous
   cases that look like octal notation.

   在 3.9.5 版的變更: Leading zeros are no longer tolerated and are
   treated as an error. IPv4 address strings are now parsed as strict
   as glibc "inet_pton()".

   version

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

      在 3.14 版的變更: Made available on the class.

   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.

      在 3.14 版的變更: Made available on the class.

   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.

   reverse_pointer

      The name of the reverse DNS PTR record for the IP address, e.g.:

         >>> ipaddress.ip_address("127.0.0.1").reverse_pointer
         '1.0.0.127.in-addr.arpa'
         >>> ipaddress.ip_address("2001:db8::1").reverse_pointer
         '1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa'

      This is the name that could be used for performing a PTR lookup,
      not the resolved hostname itself.

      在 3.5 版被加入.

   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 defined as not globally reachable by
      iana-ipv4-special-registry (for IPv4) or iana-ipv6-special-
      registry (for IPv6) with the following exceptions:

      * "is_private" is "False" for the shared address space
        ("100.64.0.0/10")

      * For IPv4-mapped IPv6-addresses the "is_private" value is
        determined by the semantics of the underlying IPv4 addresses
        and the following condition holds (see
        "IPv6Address.ipv4_mapped"):

           address.is_private == address.ipv4_mapped.is_private

      "is_private" has value opposite to "is_global", except for the
      shared address space ("100.64.0.0/10" range) where they are both
      "False".

      在 3.13 版的變更: Fixed some false positives and false
      negatives.

      * "192.0.0.0/24" is considered private with the exception of
        "192.0.0.9/32" and "192.0.0.10/32" (previously: only the
        "192.0.0.0/29" sub-range was considered private).

      * "64:ff9b:1::/48" 被視為私有。

      * "2002::/16" 被視為私有。

      * There are exceptions within "2001::/23" (otherwise considered
        private): "2001:1::1/128", "2001:1::2/128", "2001:3::/32",
        "2001:4:112::/48", "2001:20::/28", "2001:30::/28". The
        exceptions are not considered private.

   is_global

      "True" if the address is defined as globally reachable by iana-
      ipv4-special-registry (for IPv4) or iana-ipv6-special-registry
      (for IPv6) with the following exception:

      For IPv4-mapped IPv6-addresses the "is_private" value is
      determined by the semantics of the underlying IPv4 addresses and
      the following condition holds (see "IPv6Address.ipv4_mapped"):

         address.is_global == address.ipv4_mapped.is_global

      "is_global" has value opposite to "is_private", except for the
      shared address space ("100.64.0.0/10" range) where they are both
      "False".

      在 3.4 版被加入.

      在 3.13 版的變更: Fixed some false positives and false
      negatives, see "is_private" for details.

   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 noted as reserved by the IETF. For
      IPv4, this is only "240.0.0.0/4", the "Reserved" address block.
      For IPv6, this is all addresses allocated as "Reserved by IETF"
      for future use.

      備註:

        For IPv4, "is_reserved" is not related to the address block
        value of the "Reserved-by-Protocol" column in iana-ipv4
        -special-registry.

      警示:

        For IPv6, "fec0::/10" a former Site-Local scoped address
        prefix is currently excluded from that list (see
        "is_site_local" & **RFC 3879**).

   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**.

   ipv6_mapped

      "IPv4Address" object representing the IPv4-mapped IPv6 address.
      See **RFC 4291**.

      在 3.13 版被加入.

IPv4Address.__format__(fmt)

   Returns a string representation of the IP address, controlled by an
   explicit format string. *fmt* can be one of the following: "'s'",
   the default option, equivalent to "str()", "'b'" for a zero-padded
   binary string, "'X'" or "'x'" for an uppercase or lowercase
   hexadecimal representation, or "'n'", which is equivalent to "'b'"
   for IPv4 addresses and "'x'" for IPv6. For binary and hexadecimal
   representations, the form specifier "'#'" and the grouping option
   "'_'" are available. "__format__" is used by "format", "str.format"
   and f-strings.

   >>> format(ipaddress.IPv4Address('192.168.0.1'))
   '192.168.0.1'
   >>> '{:#b}'.format(ipaddress.IPv4Address('192.168.0.1'))
   '0b11000000101010000000000000000001'
   >>> f'{ipaddress.IPv6Address("2001:db8::1000"):s}'
   '2001:db8::1000'
   >>> format(ipaddress.IPv6Address('2001:db8::1000'), '_X')
   '2001_0DB8_0000_0000_0000_0000_0000_1000'
   >>> '{:#_n}'.format(ipaddress.IPv6Address('2001:db8::1000'))
   '0x2001_0db8_0000_0000_0000_0000_0000_1000'

   在 3.9 版被加入.

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"".

      Optionally, the string may also have a scope zone ID, expressed
      with a suffix "%scope_id". If present, the scope ID must be non-
      empty, and may not contain "%". See **RFC 4007** for details.
      For example, "fe80::1234%1" might identify address "fe80::1234"
      on the first link of the node.

   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')
   >>> ipaddress.IPv6Address('ff02::5678%1')
   IPv6Address('ff02::5678%1')

   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.

   For the following attributes and methods, see the corresponding
   documentation of the "IPv4Address" class:

   packed

   reverse_pointer

   version

   max_prefixlen

   is_multicast

   is_private

   is_global

      在 3.4 版被加入.

   is_unspecified

   is_reserved

   is_loopback

   is_link_local

   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".

   scope_id

      For scoped addresses as defined by **RFC 4007**, this property
      identifies the particular zone of the address's scope that the
      address belongs to, as a string. When no scope zone is
      specified, 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".

IPv6Address.__format__(fmt)

   Refer to the corresponding method documentation in "IPv4Address".

   在 3.9 版被加入.


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

Note that IPv6 scoped addresses are converted to integers without
scope zone ID.


運算子
------

Address objects support some operators.  Unless stated otherwise,
operators can only be applied between compatible objects (i.e. IPv4
with IPv4, IPv6 with IPv6).


比較運算子
~~~~~~~~~~

Address objects can be compared with the usual set of comparison
operators. Same IPv6 addresses with different scope zone IDs are not
equal. 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
   >>> IPv6Address('fe80::1234') == IPv6Address('fe80::1234%1')
   False
   >>> IPv6Address('fe80::1234%1') != IPv6Address('fe80::1234%2')
   True


算術運算子
~~~~~~~~~~

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". Network objects are *hashable*, so they can be used
as keys in dictionaries.

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, with the single exception of an all-
      zero mask which is treated as a *net mask*.  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*.

   4. A two-tuple of an address description and a netmask, where the
      address description is either a string, a 32-bits integer, a
      4-bytes packed integer, or an existing "IPv4Address" object; and
      the netmask is either an integer representing the prefix length
      (e.g. "24") or a string representing the prefix mask (e.g.
      "255.255.255.0").

   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".

   在 3.5 版的變更: Added the two-tuple form for the *address*
   constructor parameter.

   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 an "IPv4Address" object.

   netmask

      The net mask, as an "IPv4Address" object.

   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.  For networks with a mask length of 31, the
      network address and network broadcast address are also included
      in the result. Networks with a mask of 32 will return a list
      containing the single host address.

      >>> list(ip_network('192.0.2.0/29').hosts())
      [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')]
      >>> list(ip_network('192.0.2.0/31').hosts())
      [IPv4Address('192.0.2.0'), IPv4Address('192.0.2.1')]
      >>> list(ip_network('192.0.2.1/32').hosts())
      [IPv4Address('192.0.2.1')]

   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))
      [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))
      [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))
      [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')

   subnet_of(other)

      Return "True" if this network is a subnet of *other*.

      >>> a = ip_network('192.168.1.0/24')
      >>> b = ip_network('192.168.1.128/30')
      >>> b.subnet_of(a)
      True

      在 3.7 版被加入.

   supernet_of(other)

      Return "True" if this network is a supernet of *other*.

      >>> a = ip_network('192.168.1.0/24')
      >>> b = ip_network('192.168.1.128/30')
      >>> a.supernet_of(b)
      True

      在 3.7 版被加入.

   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

      在 3.7 版之後被棄用: It uses the same ordering and comparison
      algorithm as "<", "==", and ">"

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 prefix
      length, separated by a slash ("/").  The IP address is the
      network address, and the prefix length must be a single number,
      the *prefix*.  If no prefix length is provided, it's considered
      to be "/128".

      Note that currently expanded netmasks are not supported.  That
      means "2001:db00::0/24" is a valid argument while
      "2001:db00::0/ffff:ff00::" is not.

   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, big-
      endian. The interpretation is similar to an integer *address*.

   4. A two-tuple of an address description and a netmask, where the
      address description is either a string, a 128-bits integer, a
      16-bytes packed integer, or an existing "IPv6Address" object;
      and the netmask is an integer representing the prefix length.

   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.

   在 3.5 版的變更: Added the two-tuple form for the *address*
   constructor parameter.

   version

   max_prefixlen

   is_multicast

   is_private

   is_unspecified

   is_reserved

   is_loopback

   is_link_local

   network_address

   broadcast_address

   hostmask

   netmask

   with_prefixlen

   compressed

   exploded

   with_netmask

   with_hostmask

   num_addresses

   prefixlen

   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 Subnet-Router anycast address.  For networks
      with a mask length of 127, the Subnet-Router anycast address is
      also included in the result. Networks with a mask of 128 will
      return a list containing the single host address.

   overlaps(other)

   address_exclude(network)

   subnets(prefixlen_diff=1, new_prefix=None)

   supernet(prefixlen_diff=1, new_prefix=None)

   subnet_of(other)

   supernet_of(other)

   compare_networks(other)

      Refer to the corresponding attribute documentation in
      "IPv4Network".

   is_site_local

      This attribute is true for the network as a whole if it is true
      for both the network address and the broadcast address.


運算子
------

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. Network objects are ordered first by network address, then
by net mask.


疊代
~~~~

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

Interface objects are *hashable*, so they can be used as keys in
dictionaries.

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 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".


運算子
------

Interface 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
~~~~~~~~~~~~~~~~~

Interface objects can be compared with the usual set of logical
operators.

For equality comparison ("==" and "!="), both the IP address and
network must be the same for the objects to be equal.  An interface
will not compare equal to any address or network object.

For ordering ("<", ">", etc) the rules are different.  Interface and
address objects with the same IP version can be compared, and the
address objects will always sort before the interface objects.  Two
interface objects are first compared by their networks and, if those
are the same, then by their IP addresses.


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 *iterable* 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 ipaddress.AddressValueError(ValueError)

   Any value error related to the address.

exception ipaddress.NetmaskValueError(ValueError)

   Any value error related to the net mask.
