commit 6f6648e436d02bce0e49ba82f4377c0d2f586f0f
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Tue Aug 17 02:40:41 2021 -0700
committer GitHub <noreply@github.com> Tue Aug 17 02:40:41 2021 -0700
tree fe2e7b5556bbdde7815905f6192a951ae1c6d10e
parent 8516ca500eb45ecf997a471f003df02a9eb767ce

bpo-38956: don't print BooleanOptionalAction's default twice (GH-27672)


Co-authored-by: Micky Yun Chan <michan@redhat.com>
(cherry picked from commit 1512bc21d60f098a9e9f37b44a2f6a9b49a3fd4f)

Co-authored-by: Maximilian Hils <git@maximilianhils.com>

Lib/argparse.py

diff --git a/Lib/argparse.py b/Lib/argparse.py
index e3a49e7..2ded39a 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -875,7 +875,7 @@ def __init__(self,
                 _option_strings.append(option_string)
 
         if help is not None and default is not None:
-            help += f" (default: {default})"
+            help += " (default: %(default)s)"
 
         super().__init__(
             option_strings=_option_strings,