bpo-46510: Add missing test for types.TracebackType/FrameType. Calculate them directly from the caught exception. (GH-30880)

Author: iritkatriel

Lib/test/test_types.py

@@ -624,6 +624,14 @@ def test_notimplemented_type(self):
     def test_none_type(self):
         self.assertIsInstance(None, types.NoneType)
 
+    def test_traceback_and_frame_types(self):
+        try:
+            raise OSError
+        except OSError as e:
+            exc = e
+        self.assertIsInstance(exc.__traceback__, types.TracebackType)
+        self.assertIsInstance(exc.__traceback__.tb_frame, types.FrameType)
+
 
 class UnionTests(unittest.TestCase):
 

Lib/types.py

@@ -52,11 +52,9 @@ def _m(self): pass
 
 try:
     raise TypeError
-except TypeError:
-    tb = sys.exc_info()[2]
-    TracebackType = type(tb)
-    FrameType = type(tb.tb_frame)
-    tb = None; del tb
+except TypeError as exc:
+    TracebackType = type(exc.__traceback__)
+    FrameType = type(exc.__traceback__.tb_frame)
 
 # For Jython, the following two types are identical
 GetSetDescriptorType = type(FunctionType.__code__)

Misc/NEWS.d/next/Library/2022-01-25-10-59-41.bpo-46510.PM5svI.rst

@@ -0,0 +1,3 @@
+Add missing test for :class:`types.TracebackType` and
+:class:`types.FrameType`. Calculate them directly from the caught exception
+without calling :func:`sys.exc_info`.