From dd18001c308fb3bb65006c91d95f6639583a3420 Mon Sep 17 00:00:00 2001
From: Steve Dower <steve.dower@python.org>
Date: Sat, 5 Sep 2020 00:45:54 +0100
Subject: [PATCH] bpo-41627: Distinguish 32 and 64-bit user site packages on
 Windows (GH-22098)

Also fixes the error message returned when sysconfig fails to interpolate a variable correctly.
---
 Lib/site.py                                   |  3 ++-
 Lib/sysconfig.py                              | 22 +++++++++++--------
 .../2020-09-04-21-35-28.bpo-41627.sx2KN1.rst  |  2 ++
 3 files changed, 17 insertions(+), 10 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Windows/2020-09-04-21-35-28.bpo-41627.sx2KN1.rst

diff --git a/Lib/site.py b/Lib/site.py
index 8979365cafc..4c095774729 100644
--- a/Lib/site.py
+++ b/Lib/site.py
@@ -274,7 +274,8 @@ def _get_path(userbase):
     version = sys.version_info
 
     if os.name == 'nt':
-        return f'{userbase}\\Python{version[0]}{version[1]}\\site-packages'
+        ver_nodot = sys.winver.replace('.', '')
+        return f'{userbase}\\Python{ver_nodot}\\site-packages'
 
     if sys.platform == 'darwin' and sys._framework:
         return f'{userbase}/lib/python/site-packages'
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index bf04ac541e6..6c87b06634c 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -53,12 +53,12 @@ _INSTALL_SCHEMES = {
         },
     # NOTE: When modifying "purelib" scheme, update site._get_path() too.
     'nt_user': {
-        'stdlib': '{userbase}/Python{py_version_nodot}',
-        'platstdlib': '{userbase}/Python{py_version_nodot}',
-        'purelib': '{userbase}/Python{py_version_nodot}/site-packages',
-        'platlib': '{userbase}/Python{py_version_nodot}/site-packages',
-        'include': '{userbase}/Python{py_version_nodot}/Include',
-        'scripts': '{userbase}/Python{py_version_nodot}/Scripts',
+        'stdlib': '{userbase}/Python{py_version_nodot_plat}',
+        'platstdlib': '{userbase}/Python{py_version_nodot_plat}',
+        'purelib': '{userbase}/Python{py_version_nodot_plat}/site-packages',
+        'platlib': '{userbase}/Python{py_version_nodot_plat}/site-packages',
+        'include': '{userbase}/Python{py_version_nodot_plat}/Include',
+        'scripts': '{userbase}/Python{py_version_nodot_plat}/Scripts',
         'data': '{userbase}',
         },
     'posix_user': {
@@ -149,10 +149,10 @@ if _PYTHON_BUILD:
 def _subst_vars(s, local_vars):
     try:
         return s.format(**local_vars)
-    except KeyError:
+    except KeyError as var:
         try:
             return s.format(**os.environ)
-        except KeyError as var:
+        except KeyError:
             raise AttributeError('{%s}' % var) from None
 
 def _extend_dict(target_dict, other_dict):
@@ -431,6 +431,7 @@ def _init_non_posix(vars):
     vars['EXE'] = '.exe'
     vars['VERSION'] = _PY_VERSION_SHORT_NO_DOT
     vars['BINDIR'] = os.path.dirname(_safe_realpath(sys.executable))
+    vars['TZPATH'] = ''
 
 #
 # public APIs
@@ -543,10 +544,13 @@ def get_config_vars(*args):
         except AttributeError:
             # sys.abiflags may not be defined on all platforms.
             _CONFIG_VARS['abiflags'] = ''
+        try:
+            _CONFIG_VARS['py_version_nodot_plat'] = sys.winver.replace('.', '')
+        except AttributeError:
+            _CONFIG_VARS['py_version_nodot_plat'] = ''
 
         if os.name == 'nt':
             _init_non_posix(_CONFIG_VARS)
-            _CONFIG_VARS['TZPATH'] = ''
         if os.name == 'posix':
             _init_posix(_CONFIG_VARS)
         # For backward compatibility, see issue19555
diff --git a/Misc/NEWS.d/next/Windows/2020-09-04-21-35-28.bpo-41627.sx2KN1.rst b/Misc/NEWS.d/next/Windows/2020-09-04-21-35-28.bpo-41627.sx2KN1.rst
new file mode 100644
index 00000000000..043bd5e9341
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2020-09-04-21-35-28.bpo-41627.sx2KN1.rst
@@ -0,0 +1,2 @@
+The user site directory for 32-bit now includes a ``-32`` suffix to
+distinguish it from the 64-bit interpreter's directory.