Drop support for python 3.8 (#444)

Drops support for python 3.8 since it is EOL. The code refactoring is
due to ruff's formatting rules for 3.9.

.github/workflows/check.yaml

@@ -26,7 +26,6 @@ jobs:
           - "3.11"
           - "3.10"
           - "3.9"
-          - "3.8"
           - type
           - dev
           - pkg_meta

pyproject.toml

@@ -21,7 +21,7 @@ maintainers = [
   { name = "Bernát Gábor", email = "gaborjbernat@gmail.com" },
   { name = "Vineet Naik", email = "naikvin@gmail.com" },
 ]
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 classifiers = [
   "Development Status :: 5 - Production/Stable",
   "Environment :: Console",
@@ -30,7 +30,6 @@ classifiers = [
   "Operating System :: OS Independent",
   "Programming Language :: Python",
   "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",
@@ -68,7 +67,6 @@ build.hooks.vcs.version-file = "src/pipdeptree/version.py"
 version.source = "vcs"
 
 [tool.ruff]
-target-version = "py38"
 line-length = 120
 format.preview = true
 format.docstring-code-line-length = 100

src/pipdeptree/__main__.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import sys
-from typing import Sequence
+from typing import TYPE_CHECKING
 
 from pipdeptree._cli import get_options
 from pipdeptree._detect_env import detect_active_interpreter
@@ -13,6 +13,9 @@ from pipdeptree._render import render
 from pipdeptree._validate import validate
 from pipdeptree._warning import WarningPrinter, WarningType, get_warning_printer
 
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
 
 def main(args: Sequence[str] | None = None) -> int | None:
     """CLI - The main function called as entry point."""

src/pipdeptree/_cli.py

@@ -3,12 +3,15 @@ from __future__ import annotations
 import enum
 import sys
 from argparse import Action, ArgumentDefaultsHelpFormatter, ArgumentParser, Namespace
-from typing import Any, Sequence, cast
+from typing import TYPE_CHECKING, Any, cast
 
 from pipdeptree._warning import WarningType
 
 from .version import __version__
 
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
 
 class Options(Namespace):
     freeze: bool

src/pipdeptree/_discovery.py

@@ -6,12 +6,15 @@ import subprocess  # noqa: S404
 import sys
 from importlib.metadata import Distribution, distributions
 from pathlib import Path
-from typing import Iterable, Tuple
+from typing import TYPE_CHECKING
 
 from packaging.utils import canonicalize_name
 
 from pipdeptree._warning import get_warning_printer
 
+if TYPE_CHECKING:
+    from collections.abc import Iterable
+
 
 def get_installed_distributions(
     interpreter: str = str(sys.executable),
@@ -103,7 +106,7 @@ def render_invalid_metadata_text(site_dirs_with_invalid_metadata: set[str]) -> N
         print(site_dir, file=sys.stderr)  # noqa: T201
 
 
-FirstSeenWithDistsPair = Tuple[Distribution, Distribution]
+FirstSeenWithDistsPair = tuple[Distribution, Distribution]
 
 
 def render_duplicated_dist_metadata_text(

src/pipdeptree/_models/dag.py

@@ -2,9 +2,10 @@ from __future__ import annotations
 
 import sys
 from collections import defaultdict, deque
+from collections.abc import Iterator, Mapping
 from fnmatch import fnmatch
 from itertools import chain
-from typing import TYPE_CHECKING, Iterator, List, Mapping
+from typing import TYPE_CHECKING
 
 from packaging.utils import canonicalize_name
 
@@ -25,7 +26,7 @@ def render_invalid_reqs_text(dist_name_to_invalid_reqs_dict: dict[str, list[str]
             print(f'  Skipping "{invalid_req}"', file=sys.stderr)  # noqa: T201
 
 
-class PackageDAG(Mapping[DistPackage, List[ReqPackage]]):
+class PackageDAG(Mapping[DistPackage, list[ReqPackage]]):
     """
     Representation of Package dependencies as directed acyclic graph using a dict as the underlying datastructure.
 

src/pipdeptree/_models/package.py

@@ -4,7 +4,7 @@ from abc import ABC, abstractmethod
 from importlib import import_module
 from importlib.metadata import Distribution, PackageNotFoundError, metadata, version
 from inspect import ismodule
-from typing import TYPE_CHECKING, Iterator
+from typing import TYPE_CHECKING
 
 from packaging.requirements import InvalidRequirement, Requirement
 from packaging.utils import canonicalize_name
@@ -12,6 +12,7 @@ from packaging.utils import canonicalize_name
 from pipdeptree._freeze import dist_to_frozen_repr
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
     from importlib.metadata import Distribution
 
 

tests/_models/test_dag.py

@@ -1,13 +1,14 @@
 from __future__ import annotations
 
 from itertools import chain
-from typing import TYPE_CHECKING, Any, Callable, Iterator
+from typing import TYPE_CHECKING, Any, Callable
 
 import pytest
 
 from pipdeptree._models import DistPackage, PackageDAG, ReqPackage, ReversedPackageDAG
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
     from unittest.mock import Mock
 
     from tests.our_types import MockGraph

tests/conftest.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 import locale
 from pathlib import Path
 from random import shuffle
-from typing import TYPE_CHECKING, Callable, Iterator
+from typing import TYPE_CHECKING, Callable
 from unittest.mock import Mock
 
 import pytest
@@ -11,6 +11,8 @@ import pytest
 from pipdeptree._models import PackageDAG
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
+
     from tests.our_types import MockGraph
 
 

tests/our_types.py

@@ -1,8 +1,6 @@
 from __future__ import annotations
 
-from typing import Dict, List, Tuple
-
-MockGraph = Dict[Tuple[str, str], List[Tuple[str, List[Tuple[str, str]]]]]
+MockGraph = dict[tuple[str, str], list[tuple[str, list[tuple[str, str]]]]]  # pragma: no cover
 
 __all__ = [
     "MockGraph",

tests/render/test_json_tree.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Callable, Iterator
+from typing import TYPE_CHECKING, Callable
 
 import pytest
 
@@ -8,6 +8,7 @@ from pipdeptree._models.dag import PackageDAG
 from pipdeptree._render.json_tree import render_json_tree
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
     from unittest.mock import Mock
 
     from tests.our_types import MockGraph

tests/render/test_mermaid.py

@@ -1,12 +1,13 @@
 from __future__ import annotations
 
 from textwrap import dedent, indent
-from typing import TYPE_CHECKING, Callable, Iterator
+from typing import TYPE_CHECKING, Callable
 
 from pipdeptree._models import PackageDAG
 from pipdeptree._render.mermaid import render_mermaid
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
     from unittest.mock import Mock
 
     from tests.our_types import MockGraph

tests/render/test_text.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Callable, Iterator
+from typing import TYPE_CHECKING, Callable
 
 import pytest
 
@@ -9,6 +9,7 @@ from pipdeptree._models.package import Package
 from pipdeptree._render.text import render_text
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
     from unittest.mock import Mock
 
     from tests.our_types import MockGraph

tests/test_validate.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Callable, Iterator
+from typing import TYPE_CHECKING, Callable
 
 import pytest
 
@@ -8,6 +8,7 @@ from pipdeptree._models import PackageDAG
 from pipdeptree._validate import conflicting_deps, cyclic_deps, render_conflicts_text, render_cycles_text, validate
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
     from unittest.mock import Mock
 
     from tests.our_types import MockGraph

tox.toml

@@ -6,7 +6,6 @@ env_list = [
   "3.11",
   "3.10",
   "3.9",
-  "3.8",
   "type",
   "pkg_meta",
 ]