Adjust tests for the new PyCapsule_Import() behavior

A submodule not imported by its package is now imported if needed.
Errors raised during importing the module or looking up an attribute are now propagated instead of being replaced with generic ImportError or AttributeError.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: serhiy-storchaka

Lib/test/test_capi/test_capsule.py

@@ -93,49 +93,46 @@ def test_non_ascii_module_name(self):
         self.check_import(f'{name}.capsule')
 
     def test_submodule(self):
-        # Only the first component is imported; a submodule not imported
-        # by its package is not found.
-        self.assertRaises(AttributeError,
-                          _testlimitedcapi.PyCapsule_Import, 'capsule_pkg.sub.capsule')
-        # It is found after explicit import.
-        importlib.import_module('capsule_pkg.sub')
+        # A submodule not imported by its package is imported if needed.
+        self.assertNotIn('capsule_pkg.sub', sys.modules)
+        self.check_import('capsule_pkg.sub.capsule')
+        self.assertIn('capsule_pkg.sub', sys.modules)
+        # It is also found if already imported.
         self.check_import('capsule_pkg.sub.capsule')
         # A submodule imported by its package is found.
         self.check_import('capsule_autopkg.sub.capsule')
 
     def test_invalid_name(self):
         pycapsule_import = _testlimitedcapi.PyCapsule_Import
         # Non-existing module.
-        self.assertRaisesRegex(ImportError,
-            'PyCapsule_Import could not import module "capsule_nonexistent"',
+        self.assertRaisesRegex(ModuleNotFoundError,
+            "No module named 'capsule_nonexistent'",
             pycapsule_import, 'capsule_nonexistent.capsule')
         # Non-UTF-8 module name.
-        self.assertRaisesRegex(ImportError,
-            'PyCapsule_Import could not import module',
-            pycapsule_import, b'\xff\xfe.capsule')
+        self.assertRaises(UnicodeDecodeError,
+                          pycapsule_import, b'\xff\xfe.capsule')
         # Empty module name.
-        self.assertRaisesRegex(ImportError,
-            'PyCapsule_Import could not import module ""',
-            pycapsule_import, '.capsule_mod.capsule')
+        self.assertRaisesRegex(ValueError, 'Empty module name',
+                               pycapsule_import, '.capsule_mod.capsule')
         # Empty name.
-        self.assertRaisesRegex(ImportError,
-            'PyCapsule_Import could not import module ""',
-            pycapsule_import, '')
+        self.assertRaisesRegex(AttributeError, 'is not valid',
+                               pycapsule_import, '')
         # Only a dot.
-        self.assertRaisesRegex(ImportError,
-            'PyCapsule_Import could not import module ""',
-            pycapsule_import, '.')
+        self.assertRaisesRegex(ValueError, 'Empty module name',
+                               pycapsule_import, '.')
         # Non-existing attribute.
-        self.assertRaises(AttributeError,
-                          pycapsule_import, 'capsule_mod.nonexistent')
+        self.assertRaisesRegex(AttributeError, 'is not valid',
+                               pycapsule_import, 'capsule_mod.nonexistent')
         # Empty attribute name.
-        self.assertRaises(AttributeError, pycapsule_import, 'capsule_mod.')
+        self.assertRaisesRegex(AttributeError, 'is not valid',
+                               pycapsule_import, 'capsule_mod.')
         # Consecutive dots.
-        self.assertRaises(AttributeError,
-                          pycapsule_import, 'capsule_mod..capsule')
+        self.assertRaisesRegex(ModuleNotFoundError,
+            "No module named 'capsule_mod.'",
+            pycapsule_import, 'capsule_mod..capsule')
         # Attribute of an object which is not a module.
-        self.assertRaises(AttributeError,
-                          pycapsule_import, 'capsule_mod.not_capsule.capsule')
+        self.assertRaisesRegex(AttributeError, 'is not valid',
+                               pycapsule_import, 'capsule_mod.not_capsule.capsule')
         # No attribute name.
         self.assertRaisesRegex(AttributeError, 'is not valid',
                                pycapsule_import, 'capsule_mod')
@@ -162,13 +159,9 @@ def test_invalid_capsule(self):
                                pycapsule_import, 'capsule_mod.nullname')
 
     def test_error_from_import(self):
-        # The exception raised during importing the module is replaced
-        # with generic ImportError.
-        with self.assertRaises(ImportError) as cm:
-            _testlimitedcapi.PyCapsule_Import('capsule_broken.capsule')
-        self.assertEqual(str(cm.exception),
-                         'PyCapsule_Import could not import '
-                         'module "capsule_broken"')
+        # The exception raised during importing the module is propagated.
+        self.assertRaises(ZeroDivisionError,
+                          _testlimitedcapi.PyCapsule_Import, 'capsule_broken.capsule')
 
     def test_error_from_attribute_lookup(self):
         self.assertRaises(FloatingPointError,