bpo-43858: Add logging.getLevelNamesMapping() (GH-26459)

Added a function that returns a copy of a dict of logging levels.

1 files changed, 8 insertions, 0 deletions

diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index ee00a32..6d11190 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -4390,6 +4390,14 @@ class ModuleLevelMiscTest(BaseTest):
         self.assertNotIn("Cannot recover from stack overflow.", err)
         self.assertEqual(rc, 1)
 
+    def test_get_level_names_mapping(self):
+        mapping = logging.getLevelNamesMapping()
+        self.assertEqual(logging._nameToLevel, mapping)  # value is equivalent
+        self.assertIsNot(logging._nameToLevel, mapping)  # but not the internal data
+        new_mapping = logging.getLevelNamesMapping()     # another call -> another copy
+        self.assertIsNot(mapping, new_mapping)           # verify not the same object as before
+        self.assertEqual(mapping, new_mapping)           # but equivalent in value
+
 
 class LogRecordTest(BaseTest):
     def test_str_rep(self):