https://github.com/python/cpython/commit/863154c9292e70c5a8a1a3f22ef4ee42e23... commit: 863154c9292e70c5a8a1a3f22ef4ee42e2304281 branch: main author: Irit Katriel <1055913+iritkatriel@users.noreply.github.com> committer: iritkatriel <1055913+iritkatriel@users.noreply.github.com> date: 2021-08-31T21:42:08+01:00 summary: bpo-31299: make it possible to filter out frames from tracebacks (GH-28067) files: A Misc/NEWS.d/next/Library/2021-08-30-13-55-09.bpo-31299.9QzjZs.rst M Doc/library/traceback.rst M Lib/test/test_traceback.py M Lib/traceback.py diff --git a/Doc/library/traceback.rst b/Doc/library/traceback.rst index 83d5c8c6fcbd3..7b230495b7b56 100644 --- a/Doc/library/traceback.rst +++ b/Doc/library/traceback.rst @@ -357,7 +357,8 @@ capture data for later printing in a lightweight fashion. Returns a string for printing one of the frames involved in the stack. This method gets called for each frame object to be printed in the - :class:`StackSummary`. + :class:`StackSummary`. If it returns ``None``, the frame is omitted + from the output. .. versionadded:: 3.11 diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py index 5d48e9d7ff039..d1967aabb29a1 100644 --- a/Lib/test/test_traceback.py +++ b/Lib/test/test_traceback.py @@ -1514,6 +1514,34 @@ def some_inner(): s.format(), [f'{__file__}:{some_inner.__code__.co_firstlineno + 1}']) + def test_dropping_frames(self): + def f(): + 1/0 + + def g(): + try: + f() + except: + return sys.exc_info() + + exc_info = g() + + class Skip_G(traceback.StackSummary): + def format_frame(self, frame): + if frame.name == 'g': + return None + return super().format_frame(frame) + + stack = Skip_G.extract( + traceback.walk_tb(exc_info[2])).format() + + self.assertEqual(len(stack), 1) + lno = f.__code__.co_firstlineno + 1 + self.assertEqual( + stack[0], + f' File "{__file__}", line {lno}, in f\n 1/0\n' + ) + class TestTracebackException(unittest.TestCase): diff --git a/Lib/traceback.py b/Lib/traceback.py index 4ad8c9a17b349..8d83fd9b517e6 100644 --- a/Lib/traceback.py +++ b/Lib/traceback.py @@ -515,6 +515,9 @@ def format(self): last_name = None count = 0 for frame in self: + formatted_frame = self.format_frame(frame) + if formatted_frame is None: + continue if (last_file is None or last_file != frame.filename or last_line is None or last_line != frame.lineno or last_name is None or last_name != frame.name): diff --git a/Misc/NEWS.d/next/Library/2021-08-30-13-55-09.bpo-31299.9QzjZs.rst b/Misc/NEWS.d/next/Library/2021-08-30-13-55-09.bpo-31299.9QzjZs.rst new file mode 100644 index 0000000000000..1ffa0b15172ee --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-08-30-13-55-09.bpo-31299.9QzjZs.rst @@ -0,0 +1 @@ +Add option to completely drop frames from a traceback by returning ``None`` from a :meth:`~traceback.StackSummary.format_frame` override. \ No newline at end of file