Add support for Python 3.12

.github/workflows/ci.yaml

@@ -81,7 +81,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.8, 3.9, "3.10", "3.11"]
+        python-version: [3.8, 3.9, "3.10", "3.11", "3.12-dev"]
     outputs:
       python-key: ${{ steps.generate-python-key.outputs.key }}
     steps:
@@ -138,7 +138,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.8, 3.9, "3.10", "3.11"]
+        python-version: [3.8, 3.9, "3.10", "3.11", "3.12-dev"]
     steps:
       - name: Set temp directory
         run: echo "TEMP=$env:USERPROFILE\AppData\Local\Temp" >> $env:GITHUB_ENV

ChangeLog

@@ -6,6 +6,10 @@ What's New in astroid 3.0.0?
 =============================
 Release date: TBA
 
+* Add support for Python 3.12, including PEP 695 type parameter syntax.
+
+  Closes #2201
+
 * Remove support for Python 3.7.
 
   Refs #2137

astroid/brain/brain_datetime.py

@@ -0,0 +1,31 @@
+# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
+# For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE
+# Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt
+
+import textwrap
+
+from astroid.brain.helpers import register_module_extender
+from astroid.builder import AstroidBuilder
+from astroid.const import PY312_PLUS
+from astroid.manager import AstroidManager
+
+
+def datetime_transform():
+    """The datetime module was C-accelerated in Python 3.12, so we
+    lack a Python source."""
+    return AstroidBuilder(AstroidManager()).string_build(
+        textwrap.dedent(
+            """
+    class date: ...
+    class time: ...
+    class datetime(date): ...
+    class timedelta: ...
+    class tzinfo: ...
+    class timezone(tzinfo): ...
+    """
+        )
+    )
+
+
+if PY312_PLUS:
+    register_module_extender(AstroidManager(), "datetime", datetime_transform)

astroid/brain/brain_typing.py

@@ -6,14 +6,16 @@
 
 from __future__ import annotations
 
+import textwrap
 import typing
 from collections.abc import Iterator
 from functools import partial
 from typing import Final
 
 from astroid import context, extract_node, inference_tip
-from astroid.builder import _extract_single_node
-from astroid.const import PY39_PLUS
+from astroid.brain.helpers import register_module_extender
+from astroid.builder import AstroidBuilder, _extract_single_node
+from astroid.const import PY39_PLUS, PY312_PLUS
 from astroid.exceptions import (
     AttributeInferenceError,
     InferenceError,
@@ -231,7 +233,8 @@ def _looks_like_typing_alias(node: Call) -> bool:
     """
     return (
         isinstance(node.func, Name)
-        and node.func.name == "_alias"
+        # TODO: remove _DeprecatedGenericAlias when Py3.14 min
+        and node.func.name in {"_alias", "_DeprecatedGenericAlias"}
         and (
             # _alias function works also for builtins object such as list and dict
             isinstance(node.args[0], (Attribute, Name))
@@ -273,6 +276,8 @@ def infer_typing_alias(
 
     :param node: call node
     :param context: inference context
+
+    # TODO: evaluate if still necessary when Py3.12 is minimum
     """
     if (
         not isinstance(node.parent, Assign)
@@ -415,6 +420,29 @@ def infer_typing_cast(
     return node.args[1].infer(context=ctx)
 
 
+def _typing_transform():
+    return AstroidBuilder(AstroidManager()).string_build(
+        textwrap.dedent(
+            """
+    class Generic:
+        @classmethod
+        def __class_getitem__(cls, item):  return cls
+    class ParamSpec: ...
+    class ParamSpecArgs: ...
+    class ParamSpecKwargs: ...
+    class TypeAlias: ...
+    class Type:
+        @classmethod
+        def __class_getitem__(cls, item):  return cls
+    class TypeVar:
+        @classmethod
+        def __class_getitem__(cls, item):  return cls
+    class TypeVarTuple: ...
+    """
+        )
+    )
+
+
 AstroidManager().register_transform(
     Call,
     inference_tip(infer_typing_typevar_or_newtype),
@@ -442,3 +470,6 @@ def infer_typing_cast(
 AstroidManager().register_transform(
     Call, inference_tip(infer_special_alias), _looks_like_special_alias
 )
+
+if PY312_PLUS:
+    register_module_extender(AstroidManager(), "typing", _typing_transform)

astroid/const.py

@@ -10,6 +10,7 @@
 PY39_PLUS = sys.version_info >= (3, 9)
 PY310_PLUS = sys.version_info >= (3, 10)
 PY311_PLUS = sys.version_info >= (3, 11)
+PY312_PLUS = sys.version_info >= (3, 12)
 
 WIN32 = sys.platform == "win32"
 

astroid/inference.py

@@ -92,6 +92,10 @@ def infer_end(
 nodes.Lambda._infer = infer_end  # type: ignore[assignment]
 nodes.Const._infer = infer_end  # type: ignore[assignment]
 nodes.Slice._infer = infer_end  # type: ignore[assignment]
+nodes.TypeAlias._infer = infer_end  # type: ignore[assignment]
+nodes.TypeVar._infer = infer_end  # type: ignore[assignment]
+nodes.ParamSpec._infer = infer_end  # type: ignore[assignment]
+nodes.TypeVarTuple._infer = infer_end  # type: ignore[assignment]
 
 
 def _infer_sequence_helper(

astroid/nodes/__init__.py

@@ -71,6 +71,7 @@
     NamedExpr,
     NodeNG,
     Nonlocal,
+    ParamSpec,
     Pass,
     Pattern,
     Raise,
@@ -83,6 +84,9 @@
     TryFinally,
     TryStar,
     Tuple,
+    TypeAlias,
+    TypeVar,
+    TypeVarTuple,
     UnaryOp,
     Unknown,
     While,
@@ -180,6 +184,8 @@
     NamedExpr,
     NodeNG,
     Nonlocal,
+    ParamSpec,
+    TypeVarTuple,
     Pass,
     Pattern,
     Raise,
@@ -193,6 +199,8 @@
     TryFinally,
     TryStar,
     Tuple,
+    TypeAlias,
+    TypeVar,
     UnaryOp,
     Unknown,
     While,
@@ -271,6 +279,7 @@
     "NamedExpr",
     "NodeNG",
     "Nonlocal",
+    "ParamSpec",
     "Pass",
     "Position",
     "Raise",
@@ -285,6 +294,9 @@
     "TryFinally",
     "TryStar",
     "Tuple",
+    "TypeAlias",
+    "TypeVar",
+    "TypeVarTuple",
     "UnaryOp",
     "Unknown",
     "unpack_infer",

astroid/nodes/as_string.py

@@ -178,6 +178,7 @@ def visit_classdef(self, node) -> str:
         args += [n.accept(self) for n in node.keywords]
         args_str = f"({', '.join(args)})" if args else ""
         docs = self._docs_dedent(node.doc_node)
+        # TODO: handle type_params
         return "\n\n{}class {}{}:{}\n{}\n".format(
             decorate, node.name, args_str, docs, self._stmt_list(node.body)
         )
@@ -330,6 +331,7 @@ def handle_functiondef(self, node, keyword) -> str:
         if node.returns:
             return_annotation = " -> " + node.returns.as_string()
             trailer = return_annotation + ":"
+        # TODO: handle type_params
         def_format = "\n%s%s %s(%s)%s%s\n%s"
         return def_format % (
             decorate,
@@ -431,6 +433,10 @@ def visit_nonlocal(self, node) -> str:
         """return an astroid.Nonlocal node as string"""
         return f"nonlocal {', '.join(node.names)}"
 
+    def visit_paramspec(self, node: nodes.ParamSpec) -> str:
+        """return an astroid.ParamSpec node as string"""
+        return node.name.accept(self)
+
     def visit_pass(self, node) -> str:
         """return an astroid.Pass node as string"""
         return "pass"
@@ -517,6 +523,18 @@ def visit_tuple(self, node) -> str:
             return f"({node.elts[0].accept(self)}, )"
         return f"({', '.join(child.accept(self) for child in node.elts)})"
 
+    def visit_typealias(self, node: nodes.TypeAlias) -> str:
+        """return an astroid.TypeAlias node as string"""
+        return node.name.accept(self) if node.name else "_"
+
+    def visit_typevar(self, node: nodes.TypeVar) -> str:
+        """return an astroid.TypeVar node as string"""
+        return node.name.accept(self) if node.name else "_"
+
+    def visit_typevartuple(self, node: nodes.TypeVarTuple) -> str:
+        """return an astroid.TypeVarTuple node as string"""
+        return "*" + node.name.accept(self) if node.name else ""
+
     def visit_unaryop(self, node) -> str:
         """return an astroid.UnaryOp node as string"""
         if node.op == "not":