Add DeprecationWarning for WindowsRegistryFinder

Co-authored-by: rashansmith <[email protected]>

Author: tomasr8

Lib/importlib/_bootstrap_external.py

@@ -692,6 +692,14 @@ class WindowsRegistryFinder:
         '\\Modules\\{fullname}\\Debug')
     DEBUG_BUILD = (_MS_WINDOWS and '_d.pyd' in EXTENSION_SUFFIXES)
 
+    def __init__(self):
+        import warnings
+        warnings.warn("importlib.machinery.WindowsRegistryFinder is "
+                      "deprecated. Use site configuration instead. "
+                      "Future versions of Python may not enable this "
+                      "finder by default.",
+                      DeprecationWarning, stacklevel=2)
+
     @staticmethod
     def _open_registry(key):
         try:

Lib/importlib/machinery.py

@@ -33,6 +33,7 @@ def all_suffixes():
 
 def __getattr__(name):
     import warnings
+
     if name == 'DEBUG_BYTECODE_SUFFIXES':
         warnings.warn("importlib.machinery.DEBUG_BYTECODE_SUFFIXES is "
                       "deprecated. Use importlib.machinery.BYTECODE_SUFFIXES "

Lib/test/test_importlib/test_api.py

@@ -493,9 +493,14 @@ def test_util(self):
 
 
 class TestDeprecations(unittest.TestCase):
-    def test_machinery_deprecated_constants(self):
+    def test_machinery_deprecated_members(self):
         from importlib import machinery
-        for attr in ('DEBUG_BYTECODE_SUFFIXES', 'OPTIMIZED_BYTECODE_SUFFIXES'):
+        attributes = (
+            'DEBUG_BYTECODE_SUFFIXES',
+            'OPTIMIZED_BYTECODE_SUFFIXES',
+            'WindowsRegistryFinder',
+        )
+        for attr in attributes:
             with self.subTest(attr=attr):
                 with self.assertWarns(DeprecationWarning):
                     getattr(machinery, attr)