gh-102038: Skip a sometimes unnecessary stat in site.py (#102039)

Author: hauntsaninja

Lib/site.py

@@ -492,20 +492,23 @@ def venv(known_paths):
         executable = sys._base_executable = os.environ['__PYVENV_LAUNCHER__']
     else:
         executable = sys.executable
-    exe_dir, _ = os.path.split(os.path.abspath(executable))
+    exe_dir = os.path.dirname(os.path.abspath(executable))
     site_prefix = os.path.dirname(exe_dir)
     sys._home = None
     conf_basename = 'pyvenv.cfg'
-    candidate_confs = [
-        conffile for conffile in (
-            os.path.join(exe_dir, conf_basename),
-            os.path.join(site_prefix, conf_basename)
+    candidate_conf = next(
+        (
+            conffile for conffile in (
+                os.path.join(exe_dir, conf_basename),
+                os.path.join(site_prefix, conf_basename)
             )
-        if os.path.isfile(conffile)
-        ]
+            if os.path.isfile(conffile)
+        ),
+        None
+    )
 
-    if candidate_confs:
-        virtual_conf = candidate_confs[0]
+    if candidate_conf:
+        virtual_conf = candidate_conf
         system_site = "true"
         # Issue 25185: Use UTF-8, as that's what the venv module uses when
         # writing the file.

Misc/NEWS.d/next/Library/2023-02-19-01-49-46.gh-issue-102038.n3if3D.rst

@@ -0,0 +1 @@
+Skip a ``stat`` in :mod:`site` if we have already found a ``pyvenv.cfg``