bpo-43858: Add logging.getLevelNamesMapping()

Doc/library/logging.rst

@@ -1111,6 +1111,12 @@ functions.
    .. note:: If you are thinking of defining your own levels, please see the
       section on :ref:`custom-levels`.
 
+.. function:: getLevelNamesDict()
+
+   Returns the dictionary of all available level names and respective logging levels.
+
+   .. versionadded:: 3.11
+
 .. function:: getLevelName(level)
 
    Returns the textual or numeric representation of logging level *level*.

Lib/logging/__init__.py

@@ -30,14 +30,14 @@
 
 
 __all__ = ['BASIC_FORMAT', 'BufferingFormatter', 'CRITICAL', 'DEBUG', 'ERROR',
-           'FATAL', 'FileHandler', 'Filter', 'Formatter', 'Handler', 'INFO',
-           'LogRecord', 'Logger', 'LoggerAdapter', 'NOTSET', 'NullHandler',
-           'StreamHandler', 'WARN', 'WARNING', 'addLevelName', 'basicConfig',
-           'captureWarnings', 'critical', 'debug', 'disable', 'error',
-           'exception', 'fatal', 'getLevelName', 'getLogger', 'getLoggerClass',
-           'info', 'log', 'makeLogRecord', 'setLoggerClass', 'shutdown',
-           'warn', 'warning', 'getLogRecordFactory', 'setLogRecordFactory',
-           'lastResort', 'raiseExceptions']
+'FATAL', 'FileHandler', 'Filter', 'Formatter', 'Handler', 'INFO',
+'LogRecord', 'Logger', 'LoggerAdapter', 'NOTSET', 'NullHandler',
+'StreamHandler', 'WARN', 'WARNING', 'addLevelName', 'basicConfig',
+'captureWarnings', 'critical', 'debug', 'disable', 'error',
+'exception', 'fatal', 'getLevelNamesDict', 'getLevelName', 'getLogger',
+'getLoggerClass', 'info', 'log', 'makeLogRecord', 'setLoggerClass', 'shutdown',
+'warn', 'warning', 'getLogRecordFactory', 'setLogRecordFactory',
+'lastResort', 'raiseExceptions']
 
 import threading
 
@@ -116,6 +116,9 @@
     'NOTSET': NOTSET,
 }
 
+def getLevelNamesDict():
+    return _nameToLevel.copy()
+
 def getLevelName(level):
     """
     Return the textual or numeric representation of logging level 'level'.

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.getLevelNamesDict()`