From f4d8e10d0d0cc1ba0787d2350a699d9fb227a7cd Mon Sep 17 00:00:00 2001 From: Irit Katriel <1055913+iritkatriel@users.noreply.github.com> Date: Tue, 6 Jun 2023 10:26:18 +0100 Subject: [PATCH] gh-105292: Add option to make traceback.TracebackException.format_exception_only recurse into exception groups (#105294) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Co-authored-by: Erlend E. Aasland Co-authored-by: Łukasz Langa --- Doc/library/traceback.rst | 20 ++++++++++++------- Doc/whatsnew/3.13.rst | 7 +++++++ Lib/test/test_traceback.py | 14 +++++++++++++ Lib/traceback.py | 18 +++++++++++------ ...-06-04-23-20-56.gh-issue-105292.ns6XQR.rst | 2 ++ 5 files changed, 48 insertions(+), 13 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2023-06-04-23-20-56.gh-issue-105292.ns6XQR.rst diff --git a/Doc/library/traceback.rst b/Doc/library/traceback.rst index 36171a3b5a6..3eb77fc3df5 100644 --- a/Doc/library/traceback.rst +++ b/Doc/library/traceback.rst @@ -333,19 +333,24 @@ capture data for later printing in a lightweight fashion. The message indicating which exception occurred is always the last string in the output. - .. method:: format_exception_only() + .. method:: format_exception_only(*, show_group=False) Format the exception part of the traceback. The return value is a generator of strings, each ending in a newline. - Normally, the generator emits a single string; however, for - :exc:`SyntaxError` exceptions, it emits several lines that (when - printed) display detailed information about where the syntax - error occurred. + When *show_group* is ``False``, the generator normally emits a single + string; however, for :exc:`SyntaxError` exceptions, it emits several + lines that (when printed) display detailed information about where + the syntax error occurred. The message indicating which exception + occurred is always the last string in the output. - The message indicating which exception occurred is always the last - string in the output. + When *show_group* is ``True``, and the exception is an instance of + :exc:`BaseExceptionGroup`, the nested exceptions are included as + well, recursively, with indentation relative to their nesting depth. + + .. versionchanged:: 3.13 + Added the *show_group* parameter. .. versionchanged:: 3.10 Added the *compact* parameter. @@ -354,6 +359,7 @@ capture data for later printing in a lightweight fashion. Added the *max_group_width* and *max_group_depth* parameters. + :class:`StackSummary` Objects ----------------------------- diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst index 4d47f24eea7..3b19e96719a 100644 --- a/Doc/whatsnew/3.13.rst +++ b/Doc/whatsnew/3.13.rst @@ -113,6 +113,13 @@ pathlib :meth:`~pathlib.Path.rglob`. (Contributed by Barney Gale in :gh:`77609`.) +traceback +--------- + +* Add *show_group* paramter to :func:`traceback.TracebackException.format_exception_only` + to format the nested exceptions of a :exc:`BaseExceptionGroup` instance, recursively. + (Contributed by Irit Katriel in :gh:`105292`.) + Optimizations ============= diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py index 19a2be88d2c..da7d1fb5592 100644 --- a/Lib/test/test_traceback.py +++ b/Lib/test/test_traceback.py @@ -2792,6 +2792,20 @@ class TestTracebackException_ExceptionGroups(unittest.TestCase): self.assertEqual(formatted, expected) + def test_exception_group_format_exception_onlyi_recursive(self): + teg = traceback.TracebackException.from_exception(self.eg) + formatted = ''.join(teg.format_exception_only(show_group=True)).split('\n') + expected = [ + 'ExceptionGroup: eg2 (2 sub-exceptions)', + ' ExceptionGroup: eg1 (2 sub-exceptions)', + ' ZeroDivisionError: division by zero', + ' ValueError: 42', + ' ValueError: 24', + '' + ] + + self.assertEqual(formatted, expected) + def test_exception_group_format(self): teg = traceback.TracebackException.from_exception(self.eg) diff --git a/Lib/traceback.py b/Lib/traceback.py index 21e32040ee9..354754b9560 100644 --- a/Lib/traceback.py +++ b/Lib/traceback.py @@ -826,7 +826,7 @@ class TracebackException: def __str__(self): return self._str - def format_exception_only(self): + def format_exception_only(self, *, show_group=False, _depth=0): """Format the exception part of the traceback. The return value is a generator of strings, each ending in a newline. @@ -839,8 +839,10 @@ class TracebackException: The message indicating which exception occurred is always the last string in the output. """ + + indent = 3 * _depth * ' ' if self.exc_type is None: - yield _format_final_exc_line(None, self._str) + yield indent + _format_final_exc_line(None, self._str) return stype = self.exc_type.__qualname__ @@ -851,9 +853,9 @@ class TracebackException: stype = smod + '.' + stype if not issubclass(self.exc_type, SyntaxError): - yield _format_final_exc_line(stype, self._str) + yield indent + _format_final_exc_line(stype, self._str) else: - yield from self._format_syntax_error(stype) + yield from [indent + l for l in self._format_syntax_error(stype)] if ( isinstance(self.__notes__, collections.abc.Sequence) @@ -861,9 +863,13 @@ class TracebackException: ): for note in self.__notes__: note = _safe_string(note, 'note') - yield from [l + '\n' for l in note.split('\n')] + yield from [indent + l + '\n' for l in note.split('\n')] elif self.__notes__ is not None: - yield "{}\n".format(_safe_string(self.__notes__, '__notes__', func=repr)) + yield indent + "{}\n".format(_safe_string(self.__notes__, '__notes__', func=repr)) + + if self.exceptions and show_group: + for ex in self.exceptions: + yield from ex.format_exception_only(show_group=show_group, _depth=_depth+1) def _format_syntax_error(self, stype): """Format SyntaxError exceptions (internal helper).""" diff --git a/Misc/NEWS.d/next/Library/2023-06-04-23-20-56.gh-issue-105292.ns6XQR.rst b/Misc/NEWS.d/next/Library/2023-06-04-23-20-56.gh-issue-105292.ns6XQR.rst new file mode 100644 index 00000000000..c23e1ffd353 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-06-04-23-20-56.gh-issue-105292.ns6XQR.rst @@ -0,0 +1,2 @@ +Add option to :func:`traceback.format_exception_only` to recurse into the +nested exception of a :exc:`BaseExceptionGroup`.