python · vstinner · Mar 18, 2026 · Mar 18, 2026
@@ -665,12 +665,10 @@ def get_platform():
 
     For other non-POSIX platforms, currently just returns :data:`sys.platform`."""
     if os.name == 'nt':
-        if 'amd64' in sys.version.lower():
-            return 'win-amd64'
-        if '(arm)' in sys.version.lower():
-            return 'win-arm32'
-        if '(arm64)' in sys.version.lower():
-            return 'win-arm64'
+        import _sysconfig
+        platform = _sysconfig.get_platform()
+        if platform:
+            return platform
         return sys.platform
 
     if os.name != "posix" or not hasattr(os, 'uname'):

@@ -7,6 +7,7 @@
 import shutil
 import json
 import textwrap
+from unittest.mock import patch
 from copy import copy
 
 from test import support
@@ -247,19 +248,15 @@ def test_get_platform(self):
         self.assertIsInstance(actual_platform, str)
         self.assertTrue(actual_platform)
 
-        # windows XP, 32bits
+        # Windows
         os.name = 'nt'
-        sys.version = ('2.4.4 (#71, Oct 18 2006, 08:34:43) '
-                       '[MSC v.1310 32 bit (Intel)]')
-        sys.platform = 'win32'
-        self.assertEqual(get_platform(), 'win32')
-
-        # windows XP, amd64
-        os.name = 'nt'
-        sys.version = ('2.4.4 (#71, Oct 18 2006, 08:34:43) '
-                       '[MSC v.1310 32 bit (Amd64)]')
-        sys.platform = 'win32'
-        self.assertEqual(get_platform(), 'win-amd64')
+        with patch('_sysconfig.get_platform', create=True, return_value='win32'):
+            self.assertEqual(get_platform(), 'win32')
+        with patch('_sysconfig.get_platform', create=True, return_value='win-amd64'):
+            self.assertEqual(get_platform(), 'win-amd64')
+        sys.platform = 'test-plaform'
+        with patch('_sysconfig.get_platform', create=True, return_value=None):
+            self.assertEqual(get_platform(), 'test-plaform')
 
         # macbook
         os.name = 'posix'

diff --git a/Misc/NEWS.d/next/Library/2026-03-18-23-54-36.gh-issue-145410.NvLWj5.rst b/Misc/NEWS.d/next/Library/2026-03-18-23-54-36.gh-issue-145410.NvLWj5.rst
@@ -0,0 +1,3 @@
+On Windows, :func:`sysconfig.get_platform` now gets the platform from the
+``_sysconfig`` module instead of parsing :data:`sys.version` string. Patch
+by Victor Stinner.
@@ -81,11 +81,48 @@ _sysconfig_config_vars_impl(PyObject *module)
     return config;
 }
 
+#ifdef MS_WINDOWS
+/*[clinic input]
+_sysconfig.get_platform
+
+Return a string that identifies the current platform.
+[clinic start generated code]*/
+
+static PyObject *
+_sysconfig_get_platform_impl(PyObject *module)
+/*[clinic end generated code: output=4ecbbe2b77633f3e input=c0b43abda44f9a01]*/
+{
+#ifdef MS_WIN64
+#  if defined(_M_X64) || defined(_M_AMD64)
+#    define SYSCONFIG_PLATFORM "win-amd64"
+#  elif defined(_M_ARM64)
+#    define SYSCONFIG_PLATFORM "win-arm64"
+#  endif
+#endif
+
+#if defined(MS_WIN32) && !defined(MS_WIN64)
+#  if defined(_M_IX86)
+#    define SYSCONFIG_PLATFORM "win32"
+#  elif defined(_M_ARM)
+#    define SYSCONFIG_PLATFORM "win-arm32"
+#  endif
+#endif
+
+#ifdef SYSCONFIG_PLATFORM
+    return PyUnicode_FromString(SYSCONFIG_PLATFORM);
+#else
+    Py_RETURN_NONE;
+#endif
+}
+#endif  // MS_WINDOWS
+
+
 PyDoc_STRVAR(sysconfig__doc__,
 "A helper for the sysconfig module.");
 
 static struct PyMethodDef sysconfig_methods[] = {
     _SYSCONFIG_CONFIG_VARS_METHODDEF
+    _SYSCONFIG_GET_PLATFORM_METHODDEF
     {NULL, NULL}
 };
 

diff --git a/Modules/clinic/_sysconfig.c.h b/Modules/clinic/_sysconfig.c.h