From 6a90bd3a55e13715e309c4933740a16eee534e3a Mon Sep 17 00:00:00 2001
From: Tom Schraitle <tom_schr@web.de>
Date: Sun, 23 Jul 2023 09:32:43 +0200
Subject: [PATCH] Introduce ClassVar type

Use it for class variables NAMES, _LAST_NUMBER, _REGEX_TEMPLATE,
_REGEX, and _REGEX_OPTIONAL_MINOR_AND_PATCH.
---
 changelog.d/pr420.trivial.rst |  2 ++
 pyproject.toml                |  1 -
 src/semver/version.py         | 14 +++++++++-----
 3 files changed, 11 insertions(+), 6 deletions(-)
 create mode 100644 changelog.d/pr420.trivial.rst

diff --git a/changelog.d/pr420.trivial.rst b/changelog.d/pr420.trivial.rst
new file mode 100644
index 00000000..234ecdbe
--- /dev/null
+++ b/changelog.d/pr420.trivial.rst
@@ -0,0 +1,2 @@
+Introduce :py:class:`~typing.ClassVar` for some :class:`~semver.version.Version`
+class variables, mainly :data:`~semver.version.Version.NAMES` and some private.
diff --git a/pyproject.toml b/pyproject.toml
index 6b12deb0..e26c034c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,7 +14,6 @@ requires = [
 build-backend = "setuptools.build_meta"
 
 
-
 [tool.black]
 line-length = 88
 target-version = ['py37', 'py38', 'py39', 'py310', 'py311']
diff --git a/src/semver/version.py b/src/semver/version.py
index 96040cef..c84f2328 100644
--- a/src/semver/version.py
+++ b/src/semver/version.py
@@ -4,9 +4,11 @@
 from functools import wraps
 from typing import (
     Any,
+    ClassVar,
     Dict,
     Iterable,
     Optional,
+    Pattern,
     SupportsInt,
     Tuple,
     Union,
@@ -72,12 +74,14 @@ class Version:
     __slots__ = ("_major", "_minor", "_patch", "_prerelease", "_build")
 
     #: The names of the different parts of a version
-    NAMES = tuple([item[1:] for item in __slots__])
+    NAMES: ClassVar[Tuple[str, ...]] = tuple([item[1:] for item in __slots__])
 
     #: Regex for number in a prerelease
-    _LAST_NUMBER = re.compile(r"(?:[^\d]*(\d+)[^\d]*)+")
+    _LAST_NUMBER: ClassVar[Pattern] = re.compile(r"(?:[^\d]*(\d+)[^\d]*)+")
     #: Regex template for a semver version
-    _REGEX_TEMPLATE = r"""
+    _REGEX_TEMPLATE: ClassVar[
+        str
+    ] = r"""
             ^
             (?P<major>0|[1-9]\d*)
             (?:
@@ -99,12 +103,12 @@ class Version:
             $
         """
     #: Regex for a semver version
-    _REGEX = re.compile(
+    _REGEX: ClassVar[Pattern] = re.compile(
         _REGEX_TEMPLATE.format(opt_patch="", opt_minor=""),
         re.VERBOSE,
     )
     #: Regex for a semver version that might be shorter
-    _REGEX_OPTIONAL_MINOR_AND_PATCH = re.compile(
+    _REGEX_OPTIONAL_MINOR_AND_PATCH: ClassVar[Pattern] = re.compile(
         _REGEX_TEMPLATE.format(opt_patch="?", opt_minor="?"),
         re.VERBOSE,
     )