deps: drop py3.8, support py3.9+

nstarman · nstarman · commit b533e0948de7 · 2025-09-30T14:56:46.000-04:00
Signed-off-by: nstarman &lt;nstarman@users.noreply.github.com&gt;
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -16,9 +16,6 @@ jobs:
       fail-fast: false
       matrix:
         value:
-          - name: "3.8"
-            python-version: "3.8"
-            extra-install: ""
           - name: "3.9"
             python-version: "3.9"
             extra-install: ""
@@ -28,15 +25,18 @@ jobs:
           - name: "3.11"
             python-version: "3.11"
             extra-install: ""
-          - name: "3.11-pre-beartype"
-            python-version: "3.11"
-            extra-install: "pip install --upgrade --pre beartype"
           - name: "3.12"
             python-version: "3.12"
             extra-install: ""
           - name: "3.12-pre-beartype"
             python-version: "3.12"
             extra-install: "pip install --upgrade --pre beartype"
+          - name: "3.13"
+            python-version: "3.13"
+            extra-install: ""
+          - name: "3.13-pre-beartype"
+            python-version: "3.13"
+            extra-install: "pip install --upgrade --pre beartype"
 
     name: Test ${{ matrix.value.name }}
     steps:
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
@@ -3,7 +3,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.11"
+    python: "3.12"
   jobs:
     pre_build:
       # Generate the Sphinx configuration for this Jupyter Book, so it builds.
diff --git a/README.md b/README.md
@@ -17,7 +17,7 @@ If you notice any issues with the new release, please open an issue.
 
 # Installation
 
-Plum requires Python 3.8 or higher.
+Plum requires Python 3.9 or higher.
 
 ```bash
 pip install plum-dispatch
diff --git a/check_linter_assertions.py b/check_linter_assertions.py
@@ -2,8 +2,9 @@
 import subprocess
 import sys
 from collections import defaultdict
+from collections.abc import Callable
 from pathlib import Path
-from typing import Callable, Dict, List, Tuple
+from typing import Dict, List, Tuple
 
 FileLineInfo = Dict[Path, Dict[int, List[str]]]
 """type: Type of a nested dictionary that gives for a collection of files line-wise
diff --git a/plum/alias.py b/plum/alias.py
@@ -27,9 +27,7 @@
 """
 
 from functools import wraps
-from typing import List, TypeVar, Union, _type_repr
-
-from .typing import get_args
+from typing import List, TypeVar, Union, _type_repr, get_args
 
 __all__ = ["activate_union_aliases", "deactivate_union_aliases", "set_union_alias"]
 
diff --git a/plum/dispatcher.py b/plum/dispatcher.py
@@ -14,7 +14,7 @@
 
 
 _dataclass_kw_args: Dict[str, Any] = {}
-if sys.version_info >= (3, 10):  # pragma: specific no cover 3.8 3.9
+if sys.version_info >= (3, 10):  # pragma: specific no cover 3.9
     _dataclass_kw_args |= {"slots": True}
 
 
diff --git a/plum/function.py b/plum/function.py
@@ -20,7 +20,7 @@
 # `typing.Self` is available for Python 3.11 and higher.
 try:  # pragma: specific no cover 3.11
     from typing import Self
-except ImportError:  # pragma: specific no cover 3.8 3.9 3.10
+except ImportError:  # pragma: specific no cover 3.10
     Self = TypeVar("Self", bound="Function")
 
 SomeExceptionType = TypeVar("SomeExceptionType", bound=Exception)
@@ -125,7 +125,7 @@ def __doc__(self) -> Optional[str]:
         """
         try:
             self._resolve_pending_registrations()
-        except NameError:  # pragma: specific no cover 3.7 3.8 3.9
+        except NameError:  # pragma: specific no cover 3.9
             # When `staticmethod` is combined with
             # `from __future__ import annotations`, in Python 3.10 and higher
             # `staticmethod` will attempt to inherit `__doc__` (see
diff --git a/plum/method.py b/plum/method.py
@@ -1,6 +1,7 @@
 import inspect
 import typing
-from typing import Callable, List, Optional, Set, Tuple
+from collections.abc import Callable
+from typing import List, Optional, Set, Tuple
 
 from rich.padding import Padding
 from rich.text import Text
diff --git a/plum/overload.py b/plum/overload.py
@@ -1,6 +1,6 @@
 import sys
 
-if sys.version_info >= (3, 11):  # pragma: specific no cover 3.7 3.8 3.9 3.10
+if sys.version_info >= (3, 11):  # pragma: specific no cover 3.9 3.10
     from typing import get_overloads, overload
 else:  # pragma: specific no cover 3.11
     from typing_extensions import get_overloads, overload
diff --git a/plum/repr.py b/plum/repr.py
@@ -66,7 +66,7 @@ def repr_short(x) -> str:
         str: Shorter representation of `x`.
     """
     # :func:`typing._type_repr` is an internal function, but it should be available in
-    # Python versions 3.8 through 3.11.
+    # Python versions 3.9 through 3.11.
     return typing._type_repr(x)
 
 
diff --git a/plum/resolver.py b/plum/resolver.py
@@ -1,8 +1,9 @@
 import pydoc
 import sys
 import warnings
+from collections.abc import Callable
 from functools import wraps
-from typing import Callable, Optional, Tuple, Union
+from typing import Optional, Tuple, Union
 
 from rich.padding import Padding
 from rich.text import Text
diff --git a/plum/signature.py b/plum/signature.py
@@ -5,11 +5,13 @@
 from typing import Any, Callable, ClassVar, List, Set, Tuple, Union
 
 # TODO: When minimum version required is 3.11, remove `typing_extensions`.
-if sys.version_info >= (3, 11):  # pragma: specific no cover 3.7 3.8 3.9 3.10
+if sys.version_info >= (3, 11):  # pragma: specific no cover 3.9 3.10
     from typing import Self
 else:  # pragma: specific no cover 3.11
     from typing_extensions import Self
 
+from typing import get_type_hints
+
 from rich.segment import Segment
 
 import beartype.door
@@ -18,7 +20,6 @@
 from . import _is_bearable
 from .repr import repr_short, rich_repr
 from .type import is_faithful, resolve_type_hint
-from .typing import get_type_hints
 from .util import Comparable, Missing, TypeHint, wrap_lambda
 
 __all__ = ["Signature", "append_default_args"]
diff --git a/plum/type.py b/plum/type.py
@@ -2,15 +2,13 @@
 import sys
 import typing
 import warnings
-from typing import Hashable, Union
+from typing import Hashable, Union, get_args, get_origin
 
 from typing_extensions import Self, TypeGuard
 
 from beartype.vale._core._valecore import BeartypeValidator
 
-from .typing import get_args, get_origin
-
-try:  # pragma: specific no cover 3.8 3.9
+try:  # pragma: specific no cover 3.9
     from types import UnionType
 except ImportError:  # pragma: specific no cover 3.10 3.11
 
@@ -133,7 +131,7 @@ def _is_hint(x: object) -> bool:
         bool: `True` if `x` is a type hint and `False` otherwise.
     """
     try:
-        if x.__module__ == "builtins":  # pragma: specific no cover 3.8
+        if x.__module__ == "builtins":
             # Check if `x` is a subscripted built-in. We do this by checking the module
             # of the type of `x`.
             x = type(x)
@@ -188,7 +186,7 @@ def resolve_type_hint(x):
             # hint itself.
             return x
         else:
-            if origin is UnionType:  # pragma: specific no cover 3.8 3.9
+            if origin is UnionType:  # pragma: specific no cover 3.9
                 # The new union syntax was used.
                 y = args[0]
                 for arg in args[1:]:
@@ -198,18 +196,8 @@ def resolve_type_hint(x):
                 # Do not resolve the arguments for `Literal`s.
                 if origin != typing.Literal:
                     args = resolve_type_hint(args)
-                try:
-                    return origin[args]
-                except TypeError as e:  # pragma: specific no cover 3.9 3.10 3.11
-                    # In Python 3.8, the origin might be a type that cannot be
-                    # subscripted. As a workaround, we get the name of the type,
-                    # capitalize it, and try to get it from `typing`. So far, this
-                    # seems to have worked fine.
-                    if sys.version_info.minor <= 8:
-                        return getattr(typing, origin.__name__.capitalize())[args]
-                    else:  # pragma: no cover
-                        # This branch can never be reached.
-                        raise e
+
+                return origin[args]
 
     elif x is None or x is Ellipsis:
         return x
diff --git a/plum/typing.py b/plum/typing.py
diff --git a/plum/util.py b/plum/util.py
@@ -1,14 +1,10 @@
 import abc
 import sys
+from collections.abc import Callable
 from typing import Hashable, List, Sequence
 
 from typing_extensions import deprecated
 
-if sys.version_info.minor <= 8:  # pragma: specific no cover 3.9 3.10 3.11
-    from typing import Callable
-else:  # pragma: specific no cover 3.8
-    from collections.abc import Callable
-
 __all__ = [
     "Callable",
     "TypeHint",
diff --git a/pyproject.toml b/pyproject.toml
@@ -16,7 +16,7 @@ classifiers = [
 ]
 dynamic = ["version"]
 
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 dependencies = [
     "beartype>=0.16.2",
     "typing-extensions>=4.9.0",
diff --git a/tests/advanced/test_annotated.py b/tests/advanced/test_annotated.py
diff --git a/tests/test_type.py b/tests/test_type.py
@@ -29,6 +29,11 @@ class Literal(metaclass=LiteralMeta):
 )
 from plum.util import Callable
 
+skipifLT310 = pytest.mark.skipif(
+    sys.version_info < (3, 10),
+    reason="Requires Python 3.10 or higher.",
+)
+
 
 def test_resolvabletype():
     t = ResolvableType("int")
@@ -87,18 +92,7 @@ def test_is_hint():
     assert _is_hint(Callable)
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 9),
-    reason="Requires Python 3.9 or higher.",
-)
-def test_is_hint_subscripted_builtins():
-    assert _is_hint(tuple[int])
-
-
-@pytest.mark.skipif(
-    sys.version_info < (3, 10),
-    reason="Requires Python 3.10 or higher.",
-)
+@skipifLT310
 def test_is_hint_new_union():
     assert int | float
 
@@ -164,10 +158,7 @@ def test_resolve_type_hint_moduletype_recursion():
     assert resolve_type_hint(t) == t
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 10),
-    reason="Requires Python 3.10 or higher.",
-)
+@skipifLT310
 def test_resolve_type_hint_new_union():
     assert resolve_type_hint(float | int) == float | int
 
@@ -237,10 +228,7 @@ class FaithfulClass:
     assert is_faithful(FaithfulClass)
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 10),
-    reason="Requires Python 3.10 or higher.",
-)
+@skipifLT310
 def test_is_faithful_new_union():
     assert not is_faithful(int | float)
 
