Fix python -VV

* Make test_cmd_line.test_version() stricter
* Adjust documentation.

Author: vstinner

Doc/c-api/init_config.rst

@@ -116,12 +116,12 @@ Error Handling
 
    Get the *config* exit code.
 
-   Return ``0``.
+   Return ``0`` and leave *\*exitcode* unchanged.
 
    In Python 3.15, :c:func:`Py_InitializeFromInitConfig` sets an exit code if a
    command line option wants to exit Python. This is no longer the case in
-   Python 3.16. Instead, the option is processed in :c:func:`Py_RunMain`. This
-   function became useless.
+   Python 3.16. Instead, the option is now processed in :c:func:`Py_RunMain`.
+   This function became useless.
 
    .. deprecated:: next
 
@@ -787,9 +787,9 @@ PyStatus
       Exit Python with the specified exit code.
 
       .. deprecated:: next
-         :c:func:`Py_InitializeFromInitConfig` no longer sets an exit code if a
+         :c:func:`Py_InitializeFromConfig` no longer sets an exit code if a
          command line option wants to exit Python. Instead, the option is
-         processed in :c:func:`Py_RunMain`.
+         now processed in :c:func:`Py_RunMain`.
 
    Functions to handle a status:
 
@@ -807,9 +807,9 @@ PyStatus
       Is the result an exit?
 
       .. deprecated:: next
-         :c:func:`Py_InitializeFromInitConfig` no longer sets an exit code if a
+         :c:func:`Py_InitializeFromConfig` no longer sets an exit code if a
          command line option wants to exit Python. Instead, the option is
-         processed in :c:func:`Py_RunMain`.
+         now processed in :c:func:`Py_RunMain`.
 
    .. c:function:: void Py_ExitStatusException(PyStatus status)
 

Doc/whatsnew/3.16.rst

@@ -1133,7 +1133,7 @@ Deprecated C APIs
   member. :c:func:`Py_InitializeFromInitConfig` and
   :c:func:`Py_InitializeFromConfig` can no longer return an exit code.
   Instead, if a command line option wants to exit Python, the option is
-  processed in :c:func:`Py_RunMain`.
+  now processed in :c:func:`Py_RunMain`.
   (Contributed by Victor Stinner in :gh:`158080`.)
 
 * :c:func:`PyModule_GetFilename` is no longer deprecated, but using

Lib/test/test_cmd_line.py

@@ -133,11 +133,16 @@ def test_site_flag(self):
 
     @support.cpython_only
     def test_version(self):
-        version = ('Python %d.%d' % sys.version_info[:2]).encode("ascii")
-        for switch in '-V', '--version', '-VV':
-            rc, out, err = assert_python_ok(switch)
-            self.assertNotStartsWith(err, version)
-            self.assertStartsWith(out, version)
+        short_version = ('Python %d.%d' % sys.version_info[:2])
+        for switch in ('-V', '--version'):
+            with self.subTest(switch=switch):
+                rc, out, err = assert_python_ok(switch)
+                self.assertStartsWith(out, short_version.encode())
+                self.assertEqual(err, b'')
+
+        rc, out, err = assert_python_ok('-VV')
+        self.assertEqual(out.rstrip(), f"Python {sys.version}".encode())
+        self.assertEqual(err, b'')
 
     def test_verbose(self):
         # -v causes imports to write to stderr.  If the write to

Misc/NEWS.d/next/C_API/2026-09-24-15-27-35.gh-issue-158080.YIqypf.rst

@@ -3,4 +3,4 @@ Deprecate :c:func:`PyInitConfig_GetExitCode`, :c:func:`PyStatus_Exit`, and
 member. :c:func:`Py_InitializeFromInitConfig` and
 :c:func:`Py_InitializeFromConfig` can no longer return an exit code.
 Instead, if a command line option wants to exit Python, the option is
-processed in :c:func:`Py_RunMain`. Patch by Victor Stinner.
+now processed in :c:func:`Py_RunMain`. Patch by Victor Stinner.

Python/initconfig.c

@@ -2997,7 +2997,7 @@ static PyStatus
 config_parse_cmdline(PyConfig *config, PyWideStringList *warnoptions,
                      Py_ssize_t *opt_index)
 {
-    // DEFER_OPTION() only stores the first parsed deferred option
+    // Only store the first option
 #define DEFER_OPTION(OPTION) \
         do { \
             if (config->_deferred_cmdline_option == 0) { \
@@ -3143,12 +3143,6 @@ config_parse_cmdline(PyConfig *config, PyWideStringList *warnoptions,
 
         case 'V':
             print_version++;
-            if (print_version >= 2) {
-                DEFER_OPTION('W');
-            }
-            else {
-                DEFER_OPTION(c);
-            }
             break;
 
         case 'W':
@@ -3175,6 +3169,13 @@ config_parse_cmdline(PyConfig *config, PyWideStringList *warnoptions,
         }
     } while (config->_deferred_cmdline_option == 0);
 
+    if (print_version >= 2) {
+        DEFER_OPTION('W');
+    }
+    else if (print_version >= 1) {
+        DEFER_OPTION('V');
+    }
+
     if (config->run_command == NULL && config->run_module == NULL
         && _PyOS_optind < argv->length
         && wcscmp(argv->items[_PyOS_optind], L"-") != 0