From 2a4cbf17af19a01d942f9579342f77c39fbd23c4 Mon Sep 17 00:00:00 2001
From: Jakub Stasiak <jakub@stasiak.at>
Date: Mon, 18 Mar 2024 13:57:00 +0100
Subject: GH-65056: Improve the IP address' is_global/is_private documentation
(GH-113186)
* GH-65056: Improve the IP address' is_global/is_private documentation
It wasn't clear what the semantics of is_global/is_private are and, when
one gets to the bottom of it, it's not quite so simple (hence the
exceptions listed).
Co-authored-by: Petr Viktorin <encukou@gmail.com>
---
Doc/library/ipaddress.rst | 27 ++++++++++++++++++----
Lib/ipaddress.py | 58 ++++++++++++++++++++++++++++++++++++-----------
2 files changed, 68 insertions(+), 17 deletions(-)
diff --git a/Doc/library/ipaddress.rst b/Doc/library/ipaddress.rst
index 7b07a34..73f4960 100644
--- a/Doc/library/ipaddress.rst
+++ b/Doc/library/ipaddress.rst
@@ -178,15 +178,34 @@ write code that handles both IP versions correctly. Address objects are
.. attribute:: is_private
- ``True`` if the address is allocated for private networks. See
+ ``True`` if the address is defined as not globally reachable by
iana-ipv4-special-registry_ (for IPv4) or iana-ipv6-special-registry_
- (for IPv6).
+ (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 :attr:`IPv6Address.ipv4_mapped`)::
+
+ address.is_private == address.ipv4_mapped.is_private
+
+ ``is_private`` has value opposite to :attr:`is_global`, except for the shared address space
+ (``100.64.0.0/10`` range) where they are both ``False``.
.. attribute:: is_global
- ``True`` if the address is allocated for public networks. See
+ ``True`` if the address is defined as globally reachable by
iana-ipv4-special-registry_ (for IPv4) or iana-ipv6-special-registry_
- (for IPv6).
+ (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 :attr:`IPv6Address.ipv4_mapped`)::
+
+ address.is_global == address.ipv4_mapped.is_global
+
+ ``is_global`` has value opposite to :attr:`is_private`, except for the shared address space
+ (``100.64.0.0/10`` range) where they are both ``False``.
.. versionadded:: 3.4
diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index e398cc1..7d6edcf 100644
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -1333,18 +1333,38 @@ class IPv4Address(_BaseV4, _BaseAddress):
@property
@functools.lru_cache()
def is_private(self):
- """Test if this address is allocated for private networks.
+ """``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:
- Returns:
- A boolean, True if the address is reserved per
- iana-ipv4-special-registry.
+ * ``is_private`` is ``False`` for ``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 :attr:`IPv6Address.ipv4_mapped`)::
+
+ address.is_private == address.ipv4_mapped.is_private
+ ``is_private`` has value opposite to :attr:`is_global`, except for the ``100.64.0.0/10``
+ IPv4 range where they are both ``False``.
"""
return any(self in net for net in self._constants._private_networks)
@property
@functools.lru_cache()
def is_global(self):
+ """``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 :attr:`IPv6Address.ipv4_mapped`)::
+
+ address.is_global == address.ipv4_mapped.is_global
+
+ ``is_global`` has value opposite to :attr:`is_private`, except for the ``100.64.0.0/10``
+ IPv4 range where they are both ``False``.
+ """
return self not in self._constants._public_network and not self.is_private
@property
@@ -2049,13 +2069,19 @@ class IPv6Address(_BaseV6, _BaseAddress):
@property
@functools.lru_cache()
def is_private(self):
- """Test if this address is allocated for private networks.
+ """``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:
- Returns:
- A boolean, True if the address is reserved per
- iana-ipv6-special-registry, or is ipv4_mapped and is
- reserved in the iana-ipv4-special-registry.
+ * ``is_private`` is ``False`` for ``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 :attr:`IPv6Address.ipv4_mapped`)::
+
+ address.is_private == address.ipv4_mapped.is_private
+ ``is_private`` has value opposite to :attr:`is_global`, except for the ``100.64.0.0/10``
+ IPv4 range where they are both ``False``.
"""
ipv4_mapped = self.ipv4_mapped
if ipv4_mapped is not None:
@@ -2064,12 +2090,18 @@ class IPv6Address(_BaseV6, _BaseAddress):
@property
def is_global(self):
- """Test if this address is allocated for public networks.
+ """``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:
- Returns:
- A boolean, true if the address is not reserved per
- iana-ipv6-special-registry.
+ 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 :attr:`IPv6Address.ipv4_mapped`)::
+
+ address.is_global == address.ipv4_mapped.is_global
+ ``is_global`` has value opposite to :attr:`is_private`, except for the ``100.64.0.0/10``
+ IPv4 range where they are both ``False``.
"""
return not self.is_private
--
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