bpo-43858: Add logging.getLevelNamesMapping()

Doc/library/logging.rst

@@ -1111,6 +1111,14 @@ functions.
  .. note:: If you are thinking of defining your own levels, please see the
  section on :ref:`custom-levels`.
 
+.. function:: getLevelNamesMapping()
+
+ Returns a mapping from level names to their corresponding logging
+ levels. The returned mapping is copied from internal mapping on each call to this
+ function.
+
+ .. versionadded:: 3.11
+
 .. function:: getLevelName(level)
 
  Returns the textual or numeric representation of logging level *level*.

Lib/logging/__init__.py

@@ -37,7 +37,7 @@
  'exception', 'fatal', 'getLevelName', 'getLogger', 'getLoggerClass',
  'info', 'log', 'makeLogRecord', 'setLoggerClass', 'shutdown',
  'warn', 'warning', 'getLogRecordFactory', 'setLogRecordFactory',
- 'lastResort', 'raiseExceptions']
+ 'lastResort', 'raiseExceptions', 'getLevelNamesMapping']
 
 import threading
 
@@ -116,6 +116,9 @@
  'NOTSET': NOTSET,
 }
 
+def getLevelNamesMapping():
+ return _nameToLevel.copy()
+
 def getLevelName(level):
  """
  Return the textual or numeric representation of logging level 'level'.

Lib/test/test_logging.py

@@ -4390,6 +4390,10 @@ def rec():
  self.assertNotIn("Cannot recover from stack overflow.", err)
  self.assertEqual(rc, 1)
 
+ def test_get_level_names_mapping(self):
+ self.assertEqual(logging._nameToLevel, logging.getLevelNamesMapping())
+ self.assertNotEqual(id(logging._nameToLevel), id(logging.getLevelNamesMapping()))
+
 
 class LogRecordTest(BaseTest):
  def test_str_rep(self):

Misc/NEWS.d/next/Library/2021-05-31-04-51-02.bpo-43858.r7LOu6.rst

@@ -0,0 +1 @@
+Added a function that returns a copy of a dict of logging levels: func::`logging.getLevelNamesMapping()`