pythongh-114053: Fix bad interaction of PEP 695, PEP 563 and inspect.get_annotations

Author: AlexWaygood

Lib/inspect.py

@@ -280,7 +280,13 @@ def get_annotations(obj, *, globals=None, locals=None, eval_str=False):
     if globals is None:
         globals = obj_globals
     if locals is None:
-        locals = obj_locals
+        locals = obj_locals or {}
+
+    # "Inject" type parameters into the local namespace
+    # (unless they are shadowed by assignments *in* the local namespace),
+    # as a way of emulating annotation scopes when calling `eval()`
+    if type_params := getattr(obj, "__type_params__", ()):
+        locals = {param.__name__: param for param in type_params} | locals
 
     return_value = {key:
         value if not isinstance(value, str) else eval(value, globals, locals)

Lib/test/test_inspect/inspect_stringized_annotations_pep695.py

@@ -0,0 +1,23 @@
+
+from __future__ import annotations
+from typing import Callable, Unpack
+
+
+class A[T, *Ts, **P]:
+    x: T
+    y: tuple[*Ts]
+    z: Callable[P, str]
+
+
+class B[T, *Ts, **P]:
+    T = int
+    Ts = str
+    P = bytes
+    x: T
+    y: Ts
+    z: P
+
+
+def generic_function[T, *Ts, **P](
+    x: T, *y: Unpack[Ts], z: P.args, zz: P.kwargs
+) -> None: ...

Lib/test/test_inspect/test_inspect.py

@@ -47,6 +47,7 @@
 from test.test_inspect import inspect_stock_annotations
 from test.test_inspect import inspect_stringized_annotations
 from test.test_inspect import inspect_stringized_annotations_2
+from test.test_inspect import inspect_stringized_annotations_pep695
 
 
 # Functions tested in this suite:
@@ -1692,6 +1693,38 @@ def wrapper(a, b):
         self.assertEqual(inspect.get_annotations(isa.MyClassWithLocalAnnotations), {'x': 'mytype'})
         self.assertEqual(inspect.get_annotations(isa.MyClassWithLocalAnnotations, eval_str=True), {'x': int})
 
+    def test_get_annotations_with_stringized_pep695_annotations(self):
+        from typing import Unpack
+        ann_module695 = inspect_stringized_annotations_pep695
+
+        A_annotations = inspect.get_annotations(ann_module695.A, eval_str=True)
+        A_type_params = ann_module695.A.__type_params__
+        self.assertIs(A_annotations["x"], A_type_params[0])
+        self.assertEqual(A_annotations["y"].__args__[0], Unpack[A_type_params[1]])
+        self.assertIs(A_annotations["z"].__args__[0], A_type_params[2])
+
+        B_annotations = inspect.get_annotations(ann_module695.B, eval_str=True)
+        self.assertEqual(B_annotations.keys(), {"x", "y", "z"})
+        self.assertEqual(
+            set(B_annotations.values()).intersection(ann_module695.B.__type_params__),
+            set()
+        )
+
+        generic_function_annotations = inspect.get_annotations(
+            ann_module695.generic_function, eval_str=True
+        )
+        func_t_params = ann_module695.generic_function.__type_params__
+        self.assertEqual(
+            generic_function_annotations.keys(), {"x", "y", "z", "zz", "return"}
+        )
+        self.assertIs(generic_function_annotations["x"], func_t_params[0])
+        self.assertEqual(
+            generic_function_annotations["y"],
+            Unpack[func_t_params[1]]
+        )
+        self.assertIs(generic_function_annotations["z"].__origin__, func_t_params[2])
+        self.assertIs(generic_function_annotations["zz"].__origin__, func_t_params[2])
+
 
 class TestFormatAnnotation(unittest.TestCase):
     def test_typing_replacement(self):

Misc/NEWS.d/next/Library/2024-06-08-15-15-29.gh-issue-114053.WQLAFG.rst

@@ -0,0 +1,4 @@
+Fix erroneous :exc:`NameError` when calling :func:`inspect.get_annotations`
+with ``eval_str=True``` on a class that made use of :pep:`695` type
+parameters in a module that had ``from __future__ import annotations`` at
+the top of the file. Patch by Alex Waygood.