No warning, no plans to remove -b and -bb, only make them no-op

Author: sobolevn

Doc/c-api/init_config.rst

@@ -1280,6 +1280,10 @@ PyConfig
 
       Default: ``0``.
 
+      .. deprecated:: 3.15
+
+         Deprecated, will become no-op in 3.17.
+
    .. c:member:: int warn_default_encoding
 
       If non-zero, emit a :exc:`EncodingWarning` warning when :class:`io.TextIOWrapper`

Doc/using/cmdline.rst

@@ -256,12 +256,11 @@ Miscellaneous options
 
    .. deprecated-removed:: 3.15 3.17
 
-      Deprecate :option:`-b` and :option:`-bb`
-      and schedule them for removal in Python 3.17.
-      They were mainly a transition helpers for Python2 -> Python3 era.
-      In 3.17 no :exc:`BytesWarning` won't be raised for these cases.
-      If you want to check for the same things in the future,
-      use any type-checker of your choice.
+      Deprecate :option:`-b` and :option:`!-bb`
+      and schedule them to become no-op in Python 3.17.
+      These were primarily helpers for the Python 2 -> 3 transition.
+      Starting with Python 3.17, no :exc:`BytesWarning` will be raised
+      for these cases; use a type checker instead.
 
 
 .. option:: -B

Doc/whatsnew/3.15.rst

@@ -210,11 +210,10 @@ CLI
 ---
 
 * Deprecate :option:`-b` and :option:`!-bb`
-  and schedule them for removal in Python 3.17.
-  They were mainly a transition helpers for Python2 -> Python3 era.
-  In 3.17 no :exc:`BytesWarning` won't be raised for these cases.
-  If you want to check for the same things in the future,
-  use any type-checker of your choice.
+  and schedule them to become no-op in Python 3.17.
+  These were primarily helpers for the Python 2 -> 3 transition.
+  Starting with Python 3.17, no :exc:`BytesWarning` will be raised
+  for these cases; use a type checker instead.
 
   (Contributed by Nikita Sobolev in :gh:`136355`.)
 

Lib/test/test_cmd_line.py

@@ -32,12 +32,6 @@ def _kill_python_and_exit_code(p):
     return data, returncode
 
 
-b_deprecation_msg = (
-    '-b option is deprecated since Python 3.15 '
-    'and will be removed in Python 3.17'
-)
-
-
 class CmdLineTest(unittest.TestCase):
     def test_directories(self):
         assert_python_failure('.')
@@ -712,7 +706,7 @@ def run_xdev(self, *args, check_exitcode=True, xdev=True):
                               env=env)
         if check_exitcode:
             self.assertEqual(proc.returncode, 0, proc)
-        return self.maybe_remove_b_deprecation_msg(proc.stdout)
+        return proc.stdout.rstrip()
 
     @support.cpython_only
     def test_xdev(self):
@@ -795,22 +789,7 @@ def check_warnings_filters(self, cmdline_option, envvar, use_pywarning=False):
                               universal_newlines=True,
                               env=env)
         self.assertEqual(proc.returncode, 0, proc)
-        return self.maybe_remove_b_deprecation_msg(proc.stdout)
-
-    def maybe_remove_b_deprecation_msg(self, output):
-        return output.replace(b_deprecation_msg + '\n', '').rstrip()
-
-    def test_b_deprecation_msg_stderr(self):
-        for arg in ['-b', '-bb']:
-            with self.subTest(arg=arg):
-                args = (sys.executable, arg, '-c', '')
-                proc = subprocess.run(args,
-                                      stdout=subprocess.PIPE,
-                                      stderr=subprocess.PIPE,
-                                      universal_newlines=True)
-                self.assertEqual(proc.returncode, 0, proc)
-                self.assertEqual(proc.stdout, '')
-                self.assertEqual(proc.stderr.rstrip(), b_deprecation_msg)
+        return proc.stdout.rstrip()
 
     def test_warnings_filter_precedence(self):
         expected_filters = ("error::BytesWarning "

Misc/NEWS.d/next/Core_and_Builtins/2025-07-07-12-24-00.gh-issue-136355.MTcA8j.rst

@@ -1,2 +1,2 @@
 Deprecate :option:`-b` and :option:`!-bb` and schedule them
-for removal in the future versions of Python.
+to become no-op in Python 3.17.

Python/initconfig.c

@@ -256,7 +256,7 @@ static const char usage_help[] = "\
 Options (and corresponding environment variables):\n\
 -b     : issue warnings about converting bytes/bytearray to str and comparing\n\
          bytes/bytearray with str or bytes with int. (-bb: issue errors)\n\
-         deprecated since 3.15 and will be removed in 3.17\n\
+         deprecated since 3.15 and will become no-op in 3.17.\n\
 -B     : don't write .pyc files on import; also PYTHONDONTWRITEBYTECODE=x\n\
 -c cmd : program passed in as string (terminates option list)\n\
 -d     : turn on parser debugging output (for experts only, only works on\n\
@@ -2945,11 +2945,6 @@ config_parse_cmdline(PyConfig *config, PyWideStringList *warnoptions,
             return _PyStatus_EXIT(0);
 
         case 'b':
-            if (!config->bytes_warning) {
-                fprintf(stderr,
-                        "-b option is deprecated since Python 3.15 "
-                        "and will be removed in Python 3.17\n");
-            }
             config->bytes_warning++;
             break;