https://github.com/python/cpython/commit/1e79bf6c05d057c033c396e58d20618d80d392f2 commit: 1e79bf6c05d057c033c396e58d20618d80d392f2 branch: main author: Locked-chess-official <[email protected]> committer: gpshead <[email protected]> date: 2026-04-12T10:06:41-07:00 summary:
gh-139551: add support for BaseExceptionGroup in IDLE (GH-139563) Meaningfully render ExceptionGroup tracebacks in the IDLE GUI REPL. --------- Co-authored-by: Bénédikt Tran <[email protected]> Co-authored-by: Gregory P. Smith <[email protected]> files: A Misc/NEWS.d/next/IDLE/2025-10-05-19-33-39.gh-issue-139551.TX9BRc.rst M Lib/idlelib/idle_test/test_run.py M Lib/idlelib/run.py diff --git a/Lib/idlelib/idle_test/test_run.py b/Lib/idlelib/idle_test/test_run.py index 9a9d3b7b4e219c..57bf5559c0fa88 100644 --- a/Lib/idlelib/idle_test/test_run.py +++ b/Lib/idlelib/idle_test/test_run.py @@ -82,6 +82,99 @@ def test_get_multiple_message(self, mock): subtests += 1 self.assertEqual(subtests, len(data2)) # All subtests ran? + def _capture_exception(self): + """Call run.print_exception() and return its stderr output.""" + with captured_stderr() as output: + with mock.patch.object(run, 'cleanup_traceback') as ct: + ct.side_effect = lambda t, e: t + run.print_exception() + return output.getvalue() + + @force_not_colorized + def test_print_exception_group_nested(self): + try: + try: + raise ExceptionGroup('inner', [ValueError('v1')]) + except ExceptionGroup as inner: + raise ExceptionGroup('outer', [inner, TypeError('t1')]) + except ExceptionGroup: + tb = self._capture_exception() + + self.assertIn('ExceptionGroup: outer (2 sub-exceptions)', tb) + self.assertIn('ExceptionGroup: inner', tb) + self.assertIn('ValueError: v1', tb) + self.assertIn('TypeError: t1', tb) + # Verify tree structure characters. + self.assertIn('+-+---------------- 1 ----------------', tb) + self.assertIn('+---------------- 2 ----------------', tb) + self.assertIn('+------------------------------------', tb) + + @force_not_colorized + def test_print_exception_group_chaining(self): + # __cause__ on a sub-exception exercises the prefixed + # chaining-message path (margin chars on separator lines). + sub = TypeError('t1') + sub.__cause__ = ValueError('original') + try: + raise ExceptionGroup('eg1', [sub]) + except ExceptionGroup: + tb = self._capture_exception() + self.assertIn('ValueError: original', tb) + self.assertIn('| The above exception was the direct cause', tb) + self.assertIn('ExceptionGroup: eg1', tb) + + # __context__ (implicit chaining) on a sub-exception. + sub = TypeError('t2') + sub.__context__ = ValueError('first') + try: + raise ExceptionGroup('eg2', [sub]) + except ExceptionGroup: + tb = self._capture_exception() + self.assertIn('ValueError: first', tb) + self.assertIn('| During handling of the above exception', tb) + self.assertIn('ExceptionGroup: eg2', tb) + + @force_not_colorized + def test_print_exception_group_seen(self): + shared = ValueError('shared') + try: + raise ExceptionGroup('eg', [shared, shared]) + except ExceptionGroup: + tb = self._capture_exception() + + self.assertIn('ValueError: shared', tb) + self.assertIn('<exception ValueError has printed>', tb) + + @force_not_colorized + def test_print_exception_group_max_width(self): + excs = [ValueError(f'v{i}') for i in range(20)] + try: + raise ExceptionGroup('eg', excs) + except ExceptionGroup: + tb = self._capture_exception() + + self.assertIn('+---------------- 15 ----------------', tb) + self.assertIn('+---------------- ... ----------------', tb) + self.assertIn('and 5 more exceptions', tb) + self.assertNotIn('+---------------- 16 ----------------', tb) + + @force_not_colorized + def test_print_exception_group_max_depth(self): + def make_nested(depth): + if depth == 0: + return ValueError('leaf') + return ExceptionGroup(f'level{depth}', + [make_nested(depth - 1)]) + + try: + raise make_nested(15) + except ExceptionGroup: + tb = self._capture_exception() + + self.assertIn('... (max_group_depth is 10)', tb) + self.assertIn('ExceptionGroup: level15', tb) + self.assertNotIn('ValueError: leaf', tb) + # StdioFile tests. class S(str): diff --git a/Lib/idlelib/run.py b/Lib/idlelib/run.py index a30db99a619a93..e1c40fee8f4805 100644 --- a/Lib/idlelib/run.py +++ b/Lib/idlelib/run.py @@ -249,31 +249,94 @@ def print_exception(): sys.last_type, sys.last_value, sys.last_traceback = excinfo sys.last_exc = val seen = set() + exclude = ("run.py", "rpc.py", "threading.py", "queue.py", + "debugger_r.py", "bdb.py") + max_group_width = 15 + max_group_depth = 10 + group_depth = 0 + + def print_exc_group(typ, exc, tb, prefix=""): + nonlocal group_depth + group_depth += 1 + prefix2 = prefix or " " + if group_depth > max_group_depth: + print(f"{prefix2}| ... (max_group_depth is {max_group_depth})", + file=efile) + group_depth -= 1 + return + if tb: + if not prefix: + print(" + Exception Group Traceback (most recent call last):", file=efile) + else: + print(f"{prefix}| Exception Group Traceback (most recent call last):", file=efile) + tbe = traceback.extract_tb(tb) + cleanup_traceback(tbe, exclude) + for line in traceback.format_list(tbe): + for subline in line.rstrip().splitlines(): + print(f"{prefix2}| {subline}", file=efile) + lines = get_message_lines(typ, exc, tb) + for line in lines: + print(f"{prefix2}| {line}", end="", file=efile) + num_excs = len(exc.exceptions) + if num_excs <= max_group_width: + n = num_excs + else: + n = max_group_width + 1 + for i, sub in enumerate(exc.exceptions[:n], 1): + truncated = (i > max_group_width) + first_line_pre = "+-" if i == 1 else " " + title = str(i) if not truncated else '...' + print(f"{prefix2}{first_line_pre}+---------------- {title} ----------------", file=efile) + if truncated: + remaining = num_excs - max_group_width + plural = 's' if remaining > 1 else '' + print(f"{prefix2} | and {remaining} more exception{plural}", + file=efile) + need_print_underline = True + elif id(sub) not in seen: + if not prefix: + print_exc(type(sub), sub, sub.__traceback__, " ") + else: + print_exc(type(sub), sub, sub.__traceback__, prefix + " ") + need_print_underline = not isinstance(sub, BaseExceptionGroup) + else: + print(f"{prefix2} | <exception {type(sub).__name__} has printed>", file=efile) + need_print_underline = True + if need_print_underline and i == n: + print(f"{prefix2} +------------------------------------", file=efile) + group_depth -= 1 - def print_exc(typ, exc, tb): + def print_exc(typ, exc, tb, prefix=""): seen.add(id(exc)) context = exc.__context__ cause = exc.__cause__ + prefix2 = f"{prefix}| " if prefix else "" if cause is not None and id(cause) not in seen: - print_exc(type(cause), cause, cause.__traceback__) - print("\nThe above exception was the direct cause " - "of the following exception:\n", file=efile) + print_exc(type(cause), cause, cause.__traceback__, prefix) + print(f"{prefix2}\n{prefix2}The above exception was the direct cause " + f"of the following exception:\n{prefix2}", file=efile) elif (context is not None and not exc.__suppress_context__ and id(context) not in seen): - print_exc(type(context), context, context.__traceback__) - print("\nDuring handling of the above exception, " - "another exception occurred:\n", file=efile) - if tb: - tbe = traceback.extract_tb(tb) - print('Traceback (most recent call last):', file=efile) - exclude = ("run.py", "rpc.py", "threading.py", "queue.py", - "debugger_r.py", "bdb.py") - cleanup_traceback(tbe, exclude) - traceback.print_list(tbe, file=efile) - lines = get_message_lines(typ, exc, tb) - for line in lines: - print(line, end='', file=efile) + print_exc(type(context), context, context.__traceback__, prefix) + print(f"{prefix2}\n{prefix2}During handling of the above exception, " + f"another exception occurred:\n{prefix2}", file=efile) + if isinstance(exc, BaseExceptionGroup): + print_exc_group(typ, exc, tb, prefix=prefix) + else: + if tb: + print(f"{prefix2}Traceback (most recent call last):", file=efile) + tbe = traceback.extract_tb(tb) + cleanup_traceback(tbe, exclude) + if prefix: + for line in traceback.format_list(tbe): + for subline in line.rstrip().splitlines(): + print(f"{prefix}| {subline}", file=efile) + else: + traceback.print_list(tbe, file=efile) + lines = get_message_lines(typ, exc, tb) + for line in lines: + print(f"{prefix2}{line}", end="", file=efile) print_exc(typ, val, tb) diff --git a/Misc/NEWS.d/next/IDLE/2025-10-05-19-33-39.gh-issue-139551.TX9BRc.rst b/Misc/NEWS.d/next/IDLE/2025-10-05-19-33-39.gh-issue-139551.TX9BRc.rst new file mode 100644 index 00000000000000..5ea1dfc9b5100d --- /dev/null +++ b/Misc/NEWS.d/next/IDLE/2025-10-05-19-33-39.gh-issue-139551.TX9BRc.rst @@ -0,0 +1 @@ +Support rendering :exc:`BaseExceptionGroup` in IDLE. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
