Complete traceback timestamps test coverage gaps

- Include BaseException and Exception in pickle tests by removing unnecessary filtering
- Add user-derived exception classes for ImportError and AttributeError
- Tests now fully cover all built-in exception types and required user-derived classes

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: gpshead

Lib/test/test_traceback_timestamps/test_pickle.py

@@ -10,18 +10,9 @@
 class ExceptionPickleTests(unittest.TestCase):
     """Test that exception types can be pickled and unpickled with timestamps intact."""
 
-    def _get_builtin_exception_types(self):
-        """Get concrete built-in exception types (excluding abstract bases)."""
-        all_types = get_builtin_exception_types()
-        return [
-            exc
-            for exc in all_types
-            if exc not in ["BaseException", "Exception"]
-        ]
-
     def test_builtin_exception_pickle_without_timestamps(self):
         """Test that all built-in exception types can be pickled without timestamps."""
-        exception_types = self._get_builtin_exception_types()
+        exception_types = get_builtin_exception_types()
 
         for exc_name in exception_types:
             with self.subTest(exception_type=exc_name):
@@ -45,7 +36,7 @@ def test_builtin_exception_pickle_without_timestamps(self):
 
     def test_builtin_exception_pickle_with_timestamps(self):
         """Test that all built-in exception types can be pickled with timestamps."""
-        exception_types = self._get_builtin_exception_types()
+        exception_types = get_builtin_exception_types()
 
         for exc_name in exception_types:
             with self.subTest(exception_type=exc_name):

Lib/test/test_traceback_timestamps/test_user_exceptions.py

@@ -30,6 +30,16 @@ def __init__(self, errno=None, strerror=None):
             super().__init__("MyOSError")
         self.custom_data = "os_error_data"
 
+class MyImportError(ImportError):
+    def __init__(self, message="MyImportError"):
+        super().__init__(message)
+        self.custom_data = "import_error_data"
+
+class MyAttributeError(AttributeError):
+    def __init__(self, message="MyAttributeError"):
+        super().__init__(message)
+        self.custom_data = "attribute_error_data"
+
 def test_user_exception(exc_class_name):
     try:
         exc_class = globals()[exc_class_name]
@@ -64,11 +74,13 @@ class UserExceptionTests(unittest.TestCase):
 
     def test_user_derived_exceptions_without_timestamps(self):
         """Test user-derived exception classes without timestamps."""
-        user_exceptions = ["MyBaseException", "MyException", "MyOSError"]
+        user_exceptions = ["MyBaseException", "MyException", "MyOSError", "MyImportError", "MyAttributeError"]
         expected_bases = {
             "MyBaseException": "BaseException",
             "MyException": "Exception",
             "MyOSError": "OSError",
+            "MyImportError": "ImportError",
+            "MyAttributeError": "AttributeError",
         }
 
         for exc_name in user_exceptions:
@@ -96,11 +108,13 @@ def test_user_derived_exceptions_without_timestamps(self):
 
     def test_user_derived_exceptions_with_timestamps(self):
         """Test user-derived exception classes with timestamps."""
-        user_exceptions = ["MyBaseException", "MyException", "MyOSError"]
+        user_exceptions = ["MyBaseException", "MyException", "MyOSError", "MyImportError", "MyAttributeError"]
         expected_bases = {
             "MyBaseException": "BaseException",
             "MyException": "Exception",
             "MyOSError": "OSError",
+            "MyImportError": "ImportError",
+            "MyAttributeError": "AttributeError",
         }
 
         for exc_name in user_exceptions: