python
diff --git a/‎Lib/argparse.py‎
Lines changed: 19 additions & 23 deletions b/‎Lib/argparse.py‎
Lines changed: 19 additions & 23 deletions
diff --git a/‎Lib/test/test_argparse.py‎
Lines changed: 2 additions & 3 deletions b/‎Lib/test/test_argparse.py‎
Lines changed: 2 additions & 3 deletions
diff --git a/‎Misc/NEWS.d/next/Library/2021-08-17-21-41-39.bpo-44587.57OKSz.rst‎
Lines changed: 2 additions & 4 deletions b/‎Misc/NEWS.d/next/Library/2021-08-17-21-41-39.bpo-44587.57OKSz.rst‎
Lines changed: 2 additions & 4 deletions
@@ -153,26 +153,6 @@ def _copy_items(items):
 # Formatting Help
 # ===============
 
-def _add_default_to_help_string(action):
-    """
-    Add the default value to the option help message.
-
-    ArgumentDefaultsHelpFormatter and BooleanOptionalAction both want to add
-    the default value to the help message when it isn't already present.  This
-    code will do that, detecting cornercases to prevent duplicates or cases
-    where it wouldn't make sense to the end user.
-    """
-    help = action.help
-    if help is None:
-        help = ''
-
-    if '%(default)' not in help:
-        if action.default is not SUPPRESS:
-            defaulting_nargs = [OPTIONAL, ZERO_OR_MORE]
-            if action.option_strings or action.nargs in defaulting_nargs:
-                help += ' (default: %(default)s)'
-    return help
-
 
 class HelpFormatter(object):
     """Formatter for generating usage messages and argument help strings.
@@ -716,7 +696,25 @@ class ArgumentDefaultsHelpFormatter(HelpFormatter):
     """
 
     def _get_help_string(self, action):
-        return _add_default_to_help_string(action)
+        """
+        Add the default value to the option help message.
+
+        ArgumentDefaultsHelpFormatter and BooleanOptionalAction when it isn't
+        already present. This code will do that, detecting cornercases to
+        prevent duplicates or cases where it wouldn't make sense to the end
+        user.
+        """
+        help = action.help
+        if help is None:
+            help = ''
+
+        if '%(default)' not in help:
+            if action.default is not SUPPRESS:
+                defaulting_nargs = [OPTIONAL, ZERO_OR_MORE]
+                if action.option_strings or action.nargs in defaulting_nargs:
+                    help += ' (default: %(default)s)'
+        return help
+
 
 
 class MetavarTypeHelpFormatter(HelpFormatter):
@@ -907,8 +905,6 @@ def __init__(self,
             help=help,
             metavar=metavar)
 
-        self.help = _add_default_to_help_string(self)
-
 
     def __call__(self, parser, namespace, values, option_string=None):
         if option_string in self.option_strings:
 
@@ -3743,10 +3743,9 @@ class TestHelpUsage(HelpTestCase):
           -h, --help            show this help message and exit
           -w W [W ...]          w
           -x [X ...]            x
-          --foo, --no-foo       Whether to foo (default: None)
-          --bar, --no-bar       Whether to bar (default: True)
+          --foo, --no-foo       Whether to foo
+          --bar, --no-bar       Whether to bar
           -f, --foobar, --no-foobar, --barfoo, --no-barfoo
-                                (default: None)
           --bazz, --no-bazz     Bazz!
 
         group:
 
@@ -1,4 +1,2 @@
-Fix BooleanOptionalAction to not automatically add a default string when the
-default was manually specified using ``%(default)s`` or the default was set to
-SUPPRESS.  Add a default string for ``default: None`` to differentiate when
-the unset state has a different meaning.
+Fix BooleanOptionalAction to not automatically add a default string.  If a
+default string is desired, use a formatter to add it.