[Python-checkins] GH-130750: Restore quoting of choices in argparse error messages to match documentation and improve clarity (#144983)

[savannahostrowski]

https://github.com/python/cpython/commit/53a7f76501923059188922be231db855265fe9a4
commit: 53a7f76501923059188922be231db855265fe9a4
branch: main
author: Savannah Ostrowski <savan...@python.org>
committer: savannahostrowski <savan...@python.org>
date: 2026-05-04T21:51:48Z
summary:

GH-130750: Restore quoting of choices in argparse error messages to match 
documentation and improve clarity (#144983)

files:
A Misc/NEWS.d/next/Library/2026-02-19-04-40-57.gh-issue-130750.0hW52O.rst
M Lib/argparse.py
M Lib/test/test_argparse.py
M Lib/test/test_timeit.py

diff --git a/Lib/argparse.py b/Lib/argparse.py
index d91707d9eec546..9ea6b32163a9d1 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -2758,7 +2758,7 @@ def _check_value(self, action, value):
 
         if value not in choices:
             args = {'value': str(value),
-                    'choices': ', '.join(map(str, action.choices))}
+                    'choices': ', '.join(repr(str(choice)) for choice in 
action.choices)}
             msg = _('invalid choice: %(value)r (choose from %(choices)s)')
 
             if self.suggest_on_error and isinstance(value, str):
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index e0c32976fd6f0d..4799c9947dd3ee 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -1123,7 +1123,7 @@ def test_invalid_enum_value_raises_error(self):
         parser.add_argument('--color', choices=self.Color)
         self.assertRaisesRegex(
             argparse.ArgumentError,
-            r"invalid choice: 'yellow' \(choose from red, green, blue\)",
+            r"invalid choice: 'yellow' \(choose from 'red', 'green', 'blue'\)",
             parser.parse_args,
             ['--color', 'yellow'],
         )
@@ -2392,7 +2392,7 @@ def test_wrong_argument_error_with_suggestions(self):
         with self.assertRaises(ArgumentParserError) as excinfo:
             parser.parse_args(('bazz',))
         self.assertIn(
-            "error: argument foo: invalid choice: 'bazz', maybe you meant 
'baz'? (choose from bar, baz)",
+            "error: argument foo: invalid choice: 'bazz', maybe you meant 
'baz'? (choose from 'bar', 'baz')",
             excinfo.exception.stderr
         )
 
@@ -2402,7 +2402,7 @@ def test_wrong_argument_error_no_suggestions(self):
         with self.assertRaises(ArgumentParserError) as excinfo:
             parser.parse_args(('bazz',))
         self.assertIn(
-            "error: argument foo: invalid choice: 'bazz' (choose from bar, 
baz)",
+            "error: argument foo: invalid choice: 'bazz' (choose from 'bar', 
'baz')",
             excinfo.exception.stderr,
         )
 
@@ -2415,7 +2415,7 @@ def test_wrong_argument_subparsers_with_suggestions(self):
             parser.parse_args(('baz',))
         self.assertIn(
             "error: argument {foo,bar}: invalid choice: 'baz', maybe you meant"
-             " 'bar'? (choose from foo, bar)",
+             " 'bar'? (choose from 'foo', 'bar')",
             excinfo.exception.stderr,
         )
 
@@ -2427,7 +2427,7 @@ def test_wrong_argument_subparsers_no_suggestions(self):
         with self.assertRaises(ArgumentParserError) as excinfo:
             parser.parse_args(('baz',))
         self.assertIn(
-            "error: argument {foo,bar}: invalid choice: 'baz' (choose from 
foo, bar)",
+            "error: argument {foo,bar}: invalid choice: 'baz' (choose from 
'foo', 'bar')",
             excinfo.exception.stderr,
         )
 
@@ -2438,7 +2438,7 @@ def test_wrong_argument_with_suggestion_explicit(self):
             parser.parse_args(('bazz',))
         self.assertIn(
             "error: argument foo: invalid choice: 'bazz', maybe you meant"
-             " 'baz'? (choose from bar, baz)",
+             " 'baz'? (choose from 'bar', 'baz')",
             excinfo.exception.stderr,
         )
 
@@ -2458,7 +2458,7 @@ def test_suggestions_choices_int(self):
         with self.assertRaises(ArgumentParserError) as excinfo:
             parser.parse_args(('3',))
         self.assertIn(
-            "error: argument foo: invalid choice: '3' (choose from 1, 2)",
+            "error: argument foo: invalid choice: '3' (choose from '1', '2')",
             excinfo.exception.stderr,
         )
 
@@ -2468,7 +2468,7 @@ def test_suggestions_choices_mixed_types(self):
         with self.assertRaises(ArgumentParserError) as excinfo:
             parser.parse_args(('3',))
         self.assertIn(
-            "error: argument foo: invalid choice: '3' (choose from 1, 2)",
+            "error: argument foo: invalid choice: '3' (choose from '1', '2')",
             excinfo.exception.stderr,
         )
 
diff --git a/Lib/test/test_timeit.py b/Lib/test/test_timeit.py
index 81f1a9c97393d1..a2a09f9de61490 100644
--- a/Lib/test/test_timeit.py
+++ b/Lib/test/test_timeit.py
@@ -359,7 +359,7 @@ def test_main_with_time_unit(self):
                 seconds_per_increment=0.003, switches=["-u", "parsec"]
             )
         self.assertIn(
-            "choose from nsec, usec, msec, sec", error_stringio.getvalue()
+            "choose from 'nsec', 'usec', 'msec', 'sec'", 
error_stringio.getvalue()
         )
 
     def test_main_exception(self):
diff --git 
a/Misc/NEWS.d/next/Library/2026-02-19-04-40-57.gh-issue-130750.0hW52O.rst 
b/Misc/NEWS.d/next/Library/2026-02-19-04-40-57.gh-issue-130750.0hW52O.rst
new file mode 100644
index 00000000000000..8bca48ab159476
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-02-19-04-40-57.gh-issue-130750.0hW52O.rst
@@ -0,0 +1,2 @@
+Restore quoting of choices in :mod:`argparse` error messages for improved 
clarity and consistency with documentation.
+

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