gh-92041: Resolve frame modules from globals

Author: mdeck

Lib/inspect.py

@@ -930,6 +930,14 @@ def getmodule(object, _filename=None):
     """Return the module an object was defined in, or None if not found."""
     if ismodule(object):
         return object
+    if istraceback(object):
+        object = object.tb_frame
+    if isframe(object):
+        object_globals = object.f_globals
+        module = sys.modules.get(object_globals.get('__name__'))
+        if module is not None and module.__dict__ is object_globals:
+            return module
+        return None
     if hasattr(object, '__module__'):
         return sys.modules.get(object.__module__)
 

Lib/test/test_inspect/test_inspect.py

@@ -831,6 +831,22 @@ def test_getmodule(self):
         self.assertEqual(inspect.getmodule(str), sys.modules["builtins"])
         # Check filename override
         self.assertEqual(inspect.getmodule(None, modfile), mod)
+        # Check frame and traceback objects
+        self.assertIs(inspect.getmodule(inspect.currentframe()),
+                      sys.modules[__name__])
+        try:
+            1 / 0
+        except ZeroDivisionError as error:
+            self.assertIs(inspect.getmodule(error.__traceback__),
+                          sys.modules[__name__])
+
+    def test_getmodule_unregistered_exec_frame(self):
+        namespace = {"inspect": inspect, "__name__": "not_registered"}
+        exec(compile("frame = inspect.currentframe()", modfile, "exec"),
+             namespace)
+        # The frame globals are authoritative, even though the code filename
+        # happens to match an imported module.
+        self.assertIsNone(inspect.getmodule(namespace["frame"]))
 
     def test_getmodule_file_not_found(self):
         # See bpo-45406

Misc/NEWS.d/next/Library/2026-08-14-16-30-00.gh-issue-92041.rst

@@ -0,0 +1 @@
+Improve :func:`inspect.getmodule` performance for frame and traceback objects by resolving their module directly from the frame globals.