Drop support for Python 3.8 (#2443)

Also remove constants `PY38`, `PY39_PLUS`, and `PYPY_7_3_11_PLUS`.

Author: jacobtylerwalls

.github/workflows/ci.yaml

@@ -81,7 +81,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.8, 3.9, "3.10", "3.11", "3.12"]
+        python-version: [3.9, "3.10", "3.11", "3.12"]
     outputs:
       python-key: ${{ steps.generate-python-key.outputs.key }}
     steps:
@@ -138,7 +138,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.8, 3.9, "3.10", "3.11", "3.12"]
+        python-version: [3.9, "3.10", "3.11", "3.12"]
     steps:
       - name: Set temp directory
         run: echo "TEMP=$env:USERPROFILE\AppData\Local\Temp" >> $env:GITHUB_ENV
@@ -192,7 +192,7 @@ jobs:
       fail-fast: false
       matrix:
         # We only test on the lowest and highest supported PyPy versions
-        python-version: ["pypy3.8", "pypy3.10"]
+        python-version: ["pypy3.9", "pypy3.10"]
     steps:
       - name: Check out code from GitHub
         uses: actions/[email protected]

.pre-commit-config.yaml

@@ -27,7 +27,7 @@ repos:
     hooks:
       - id: pyupgrade
         exclude: tests/testdata
-        args: [--py38-plus]
+        args: [--py39-plus]
   - repo: https://github.com/Pierre-Sassoulas/black-disable-checker/
     rev: v1.1.3
     hooks:

ChangeLog

@@ -7,14 +7,16 @@ What's New in astroid 3.3.0?
 ============================
 Release date: TBA
 
+* Remove support for Python 3.8 (and constants `PY38`, `PY39_PLUS`, and `PYPY_7_3_11_PLUS`).
+
+  Refs #2443
 
 
 What's New in astroid 3.2.3?
 ============================
 Release date: TBA
 
 
-
 What's New in astroid 3.2.2?
 ============================
 Release date: 2024-05-20

astroid/_backport_stdlib_names.py

@@ -346,11 +346,7 @@
     }
 )
 
-if sys.version_info[:2] == (3, 7):
-    stdlib_module_names = PY_3_7
-elif sys.version_info[:2] == (3, 8):
-    stdlib_module_names = PY_3_8
-elif sys.version_info[:2] == (3, 9):
+if sys.version_info[:2] == (3, 9):
     stdlib_module_names = PY_3_9
 else:
     raise AssertionError("This module is only intended as a backport for Python <= 3.9")

astroid/brain/brain_builtin_inference.py

@@ -7,9 +7,9 @@
 from __future__ import annotations
 
 import itertools
-from collections.abc import Callable, Iterable
+from collections.abc import Callable, Iterable, Iterator
 from functools import partial
-from typing import TYPE_CHECKING, Any, Iterator, NoReturn, Type, Union, cast
+from typing import TYPE_CHECKING, Any, NoReturn, Union, cast
 
 from astroid import arguments, helpers, inference_tip, nodes, objects, util
 from astroid.builder import AstroidBuilder
@@ -40,10 +40,10 @@
 ]
 
 BuiltContainers = Union[
-    Type[tuple],
-    Type[list],
-    Type[set],
-    Type[frozenset],
+    type[tuple],
+    type[list],
+    type[set],
+    type[frozenset],
 ]
 
 CopyResult = Union[

astroid/brain/brain_collections.py

@@ -6,7 +6,6 @@
 
 from astroid.brain.helpers import register_module_extender
 from astroid.builder import extract_node, parse
-from astroid.const import PY39_PLUS
 from astroid.context import InferenceContext
 from astroid.exceptions import AttributeInferenceError
 from astroid.manager import AstroidManager
@@ -61,9 +60,7 @@ def __add__(self, other): pass
         def __iadd__(self, other): pass
         def __mul__(self, other): pass
         def __imul__(self, other): pass
-        def __rmul__(self, other): pass"""
-    if PY39_PLUS:
-        base_deque_class += """
+        def __rmul__(self, other): pass
         @classmethod
         def __class_getitem__(self, item): return cls"""
     return base_deque_class
@@ -73,9 +70,7 @@ def _ordered_dict_mock():
     base_ordered_dict_class = """
     class OrderedDict(dict):
         def __reversed__(self): return self[::-1]
-        def move_to_end(self, key, last=False): pass"""
-    if PY39_PLUS:
-        base_ordered_dict_class += """
+        def move_to_end(self, key, last=False): pass
         @classmethod
         def __class_getitem__(cls, item): return cls"""
     return base_ordered_dict_class
@@ -116,11 +111,10 @@ def easy_class_getitem_inference(node, context: InferenceContext | None = None):
 def register(manager: AstroidManager) -> None:
     register_module_extender(manager, "collections", _collections_transform)
 
-    if PY39_PLUS:
-        # Starting with Python39 some objects of the collection module are subscriptable
-        # thanks to the __class_getitem__ method but the way it is implemented in
-        # _collection_abc makes it difficult to infer. (We would have to handle AssignName inference in the
-        # getitem method of the ClassDef class) Instead we put here a mock of the __class_getitem__ method
-        manager.register_transform(
-            ClassDef, easy_class_getitem_inference, _looks_like_subscriptable
-        )
+    # Starting with Python39 some objects of the collection module are subscriptable
+    # thanks to the __class_getitem__ method but the way it is implemented in
+    # _collection_abc makes it difficult to infer. (We would have to handle AssignName inference in the
+    # getitem method of the ClassDef class) Instead we put here a mock of the __class_getitem__ method
+    manager.register_transform(
+        ClassDef, easy_class_getitem_inference, _looks_like_subscriptable
+    )

astroid/brain/brain_dataclasses.py

@@ -15,11 +15,11 @@
 from __future__ import annotations
 
 from collections.abc import Iterator
-from typing import Literal, Tuple, Union
+from typing import Literal, Union
 
 from astroid import bases, context, nodes
 from astroid.builder import parse
-from astroid.const import PY39_PLUS, PY310_PLUS
+from astroid.const import PY310_PLUS
 from astroid.exceptions import AstroidSyntaxError, InferenceError, UseInferenceDefault
 from astroid.inference_tip import inference_tip
 from astroid.manager import AstroidManager
@@ -28,8 +28,8 @@
 
 _FieldDefaultReturn = Union[
     None,
-    Tuple[Literal["default"], nodes.NodeNG],
-    Tuple[Literal["default_factory"], nodes.Call],
+    tuple[Literal["default"], nodes.NodeNG],
+    tuple[Literal["default_factory"], nodes.Call],
 ]
 
 DATACLASSES_DECORATORS = frozenset(("dataclass",))
@@ -539,22 +539,12 @@ def _get_field_default(field_call: nodes.Call) -> _FieldDefaultReturn:
 
 def _is_class_var(node: nodes.NodeNG) -> bool:
     """Return True if node is a ClassVar, with or without subscripting."""
-    if PY39_PLUS:
-        try:
-            inferred = next(node.infer())
-        except (InferenceError, StopIteration):
-            return False
-
-        return getattr(inferred, "name", "") == "ClassVar"
+    try:
+        inferred = next(node.infer())
+    except (InferenceError, StopIteration):
+        return False
 
-    # Before Python 3.9, inference returns typing._SpecialForm instead of ClassVar.
-    # Our backup is to inspect the node's structure.
-    return isinstance(node, nodes.Subscript) and (
-        isinstance(node.value, nodes.Name)
-        and node.value.name == "ClassVar"
-        or isinstance(node.value, nodes.Attribute)
-        and node.value.attrname == "ClassVar"
-    )
+    return getattr(inferred, "name", "") == "ClassVar"
 
 
 def _is_keyword_only_sentinel(node: nodes.NodeNG) -> bool:

astroid/brain/brain_hashlib.py

@@ -4,13 +4,11 @@
 
 from astroid.brain.helpers import register_module_extender
 from astroid.builder import parse
-from astroid.const import PY39_PLUS
 from astroid.manager import AstroidManager
 
 
 def _hashlib_transform():
-    maybe_usedforsecurity = ", usedforsecurity=True" if PY39_PLUS else ""
-    init_signature = f"value=''{maybe_usedforsecurity}"
+    init_signature = "value='', usedforsecurity=True"
     digest_signature = "self"
     shake_digest_signature = "self, length"
 
@@ -54,13 +52,13 @@ def digest_size(self):
     blake2b_signature = (
         "data=b'', *, digest_size=64, key=b'', salt=b'', "
         "person=b'', fanout=1, depth=1, leaf_size=0, node_offset=0, "
-        f"node_depth=0, inner_size=0, last_node=False{maybe_usedforsecurity}"
+        "node_depth=0, inner_size=0, last_node=False, usedforsecurity=True"
     )
 
     blake2s_signature = (
         "data=b'', *, digest_size=32, key=b'', salt=b'', "
         "person=b'', fanout=1, depth=1, leaf_size=0, node_offset=0, "
-        f"node_depth=0, inner_size=0, last_node=False{maybe_usedforsecurity}"
+        "node_depth=0, inner_size=0, last_node=False, usedforsecurity=True"
     )
 
     shake_algorithms = dict.fromkeys(

astroid/brain/brain_re.py

@@ -7,7 +7,7 @@
 from astroid import context, inference_tip, nodes
 from astroid.brain.helpers import register_module_extender
 from astroid.builder import _extract_single_node, parse
-from astroid.const import PY39_PLUS, PY311_PLUS
+from astroid.const import PY311_PLUS
 from astroid.manager import AstroidManager
 
 
@@ -84,9 +84,8 @@ def infer_pattern_match(node: nodes.Call, ctx: context.InferenceContext | None =
         end_lineno=node.end_lineno,
         end_col_offset=node.end_col_offset,
     )
-    if PY39_PLUS:
-        func_to_add = _extract_single_node(CLASS_GETITEM_TEMPLATE)
-        class_def.locals["__class_getitem__"] = [func_to_add]
+    func_to_add = _extract_single_node(CLASS_GETITEM_TEMPLATE)
+    class_def.locals["__class_getitem__"] = [func_to_add]
     return iter([class_def])
 
 

astroid/brain/brain_regex.py

@@ -7,7 +7,6 @@
 from astroid import context, inference_tip, nodes
 from astroid.brain.helpers import register_module_extender
 from astroid.builder import _extract_single_node, parse
-from astroid.const import PY39_PLUS
 from astroid.manager import AstroidManager
 
 
@@ -83,9 +82,8 @@ def infer_pattern_match(node: nodes.Call, ctx: context.InferenceContext | None =
         end_lineno=node.end_lineno,
         end_col_offset=node.end_col_offset,
     )
-    if PY39_PLUS:
-        func_to_add = _extract_single_node(CLASS_GETITEM_TEMPLATE)
-        class_def.locals["__class_getitem__"] = [func_to_add]
+    func_to_add = _extract_single_node(CLASS_GETITEM_TEMPLATE)
+    class_def.locals["__class_getitem__"] = [func_to_add]
     return iter([class_def])