feat: drop Python 3.8 (#1157)

Author: henryiii

.github/workflows/perf.yml

@@ -25,7 +25,6 @@ jobs:
         name: Install Pythons
         with:
           python-version: |
-            3.8
             3.9
             3.10
             3.11

.github/workflows/test.yml

@@ -24,7 +24,7 @@ jobs:
       matrix:
         os: [Ubuntu, Windows, macOS]
         python_version:
-          ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "3.13t", "3.14t", "pypy3.8", "pypy3.9", "pypy3.10", "pypy3.11"]
+          ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "3.13t", "3.14t", "pypy3.9", "pypy3.10", "pypy3.11"]
         include:
           - os: Ubuntu
             python_version: "3.11.0"

asv.conf.json

@@ -15,5 +15,5 @@
             "PYTHONHASHSEED": ["0"]
         }
     },
-    "pythons": ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
+    "pythons": ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
 }

noxfile.py

@@ -20,12 +20,15 @@
 import time
 import urllib.request
 from pathlib import Path
-from typing import IO, Generator
+from typing import IO, TYPE_CHECKING
 
 import nox
 
 import packaging.version  # will always be present with nox
 
+if TYPE_CHECKING:
+    from collections.abc import Generator
+
 nox.needs_version = ">=2025.02.09"
 nox.options.reuse_existing_virtualenvs = True
 nox.options.default_venv_backend = "uv|virtualenv"
@@ -39,7 +42,6 @@
         *PYTHON_VERSIONS,
         "3.13t",
         "3.14t",
-        "pypy3.8",
         "pypy3.9",
         "pypy3.10",
         "pypy3.11",

pyproject.toml

@@ -9,15 +9,14 @@ description = "Core utilities for Python packages"
 dynamic = ["version"]
 license = "Apache-2.0 OR BSD-2-Clause"
 readme = "README.rst"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 authors = [{name = "Donald Stufft", email = "donald@stufft.io"}]
 classifiers = [
   "Development Status :: 5 - Production/Stable",
   "Intended Audience :: Developers",
   "Programming Language :: Python",
   "Programming Language :: Python :: 3",
   "Programming Language :: Python :: 3 :: Only",
-  "Programming Language :: Python :: 3.8",
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
@@ -48,7 +47,6 @@ test = [
 ]
 docs = [
   "furo",
-  "typing-extensions>=4.1.0; python_version < '3.9'",
 ]
 benchmark = [
   "asv",
@@ -111,7 +109,7 @@ markers = ["property: property-based tests (opt-in)"]
 strict = true
 enable_error_code = ["ignore-without-code", "redundant-expr", "truthy-bool"]
 warn_unused_ignores = true
-python_version = "3.8"
+python_version = "3.9"
 files = ["src", "tests", "noxfile.py"]
 
 [[tool.mypy.overrides]]

src/packaging/_manylinux.py

@@ -7,10 +7,13 @@
 import re
 import sys
 import warnings
-from typing import Generator, Iterator, NamedTuple, Sequence
+from typing import TYPE_CHECKING, NamedTuple
 
 from ._elffile import EIClass, EIData, ELFFile, EMachine
 
+if TYPE_CHECKING:
+    from collections.abc import Generator, Iterator, Sequence
+
 EF_ARM_ABIMASK = 0xFF000000
 EF_ARM_ABI_VER5 = 0x05000000
 EF_ARM_ABI_FLOAT_HARD = 0x00000400

src/packaging/_musllinux.py

@@ -10,10 +10,13 @@
 import re
 import subprocess
 import sys
-from typing import Iterator, NamedTuple, Sequence
+from typing import TYPE_CHECKING, NamedTuple
 
 from ._elffile import ELFFile
 
+if TYPE_CHECKING:
+    from collections.abc import Iterator, Sequence
+
 
 class _MuslVersion(NamedTuple):
     major: int

src/packaging/_parser.py

@@ -7,7 +7,8 @@
 from __future__ import annotations
 
 import ast
-from typing import List, Literal, NamedTuple, Sequence, Tuple, Union
+from collections.abc import Sequence
+from typing import Literal, NamedTuple, Union
 
 from ._tokenizer import DEFAULT_RULES, Tokenizer
 
@@ -79,9 +80,9 @@ def serialize(self) -> str:
 
 MarkerLogical = Literal["and", "or"]
 MarkerVar = Union[Variable, Value]
-MarkerItem = Tuple[MarkerVar, Op, MarkerVar]
+MarkerItem = tuple[MarkerVar, Op, MarkerVar]
 MarkerAtom = Union[MarkerItem, Sequence["MarkerAtom"]]
-MarkerList = List[Union["MarkerList", MarkerAtom, MarkerLogical]]
+MarkerList = list[Union["MarkerList", MarkerAtom, MarkerLogical]]
 
 
 class ParsedRequirement(NamedTuple):

src/packaging/_tokenizer.py

@@ -3,10 +3,13 @@
 import contextlib
 import re
 from dataclasses import dataclass
-from typing import Generator, Mapping, NoReturn
+from typing import TYPE_CHECKING, NoReturn
 
 from .specifiers import Specifier
 
+if TYPE_CHECKING:
+    from collections.abc import Generator, Mapping
+
 
 @dataclass
 class Token:

src/packaging/markers.py

@@ -8,14 +8,18 @@
 import os
 import platform
 import sys
-from typing import AbstractSet, Callable, Literal, Mapping, TypedDict, Union, cast
+from collections.abc import Set as AbstractSet
+from typing import TYPE_CHECKING, Callable, Literal, TypedDict, Union, cast
 
 from ._parser import MarkerAtom, MarkerList, Op, Value, Variable
 from ._parser import parse_marker as _parse_marker
 from ._tokenizer import ParserSyntaxError
 from .specifiers import InvalidSpecifier, Specifier
 from .utils import canonicalize_name
 
+if TYPE_CHECKING:
+    from collections.abc import Mapping
+
 __all__ = [
     "Environment",
     "EvaluateContext",
@@ -459,14 +463,15 @@ def evaluate(
             "dict[str, str | AbstractSet[str]]", default_environment()
         )
         if context == "lock_file":
-            current_environment.update(
-                extras=frozenset(), dependency_groups=frozenset()
-            )
+            current_environment |= {
+                "extras": frozenset(),
+                "dependency_groups": frozenset(),
+            }
         elif context == "metadata":
             current_environment["extra"] = ""
 
         if environment is not None:
-            current_environment.update(environment)
+            current_environment |= environment
             if "extra" in current_environment:
                 # The API used to allow setting extra to None. We need to handle
                 # this case for backwards compatibility. Also skip running