From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Thu, 26 Jun 2025 16:40:09 +0000 (+0200)
Subject: [3.14] gh-129958: New syntax error in format spec applies to both f-strings and t... 
X-Git-Tag: v3.14.0b4~89
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=204545317144b90942d0a7265e1433a831cfeb5d;p=thirdparty%2FPython%2Fcpython.git

[3.14] gh-129958: New syntax error in format spec applies to both f-strings and t-strings (GH-135570) (#135982)

(cherry picked from commit fb9e292919d82326acea456aa071c9af6aff5626)

Co-authored-by: Dylan <dylwil3@gmail.com>
Co-authored-by: Tomas R. <tomas.roun8@gmail.com>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
---

diff --git a/Lib/test/test_tstring.py b/Lib/test/test_tstring.py
index e72a1ea54176..aabae3855673 100644
--- a/Lib/test/test_tstring.py
+++ b/Lib/test/test_tstring.py
@@ -219,6 +219,7 @@ class TestTString(unittest.TestCase, TStringBaseCase):
             ("t'{lambda:1}'", "t-string: lambda expressions are not allowed "
                               "without parentheses"),
             ("t'{x:{;}}'", "t-string: expecting a valid expression after '{'"),
+            ("t'{1:d\n}'", "t-string: newlines are not allowed in format specifiers")
         ):
             with self.subTest(case), self.assertRaisesRegex(SyntaxError, err):
                 eval(case)
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-24-06-41-47.gh-issue-129958.EaJuS0.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-24-06-41-47.gh-issue-129958.EaJuS0.rst
new file mode 100644
index 000000000000..70b3e99425df
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-24-06-41-47.gh-issue-129958.EaJuS0.rst
@@ -0,0 +1,2 @@
+Differentiate between t-strings and f-strings in syntax error for newlines
+in format specifiers of single-quoted interpolated strings.
diff --git a/Parser/lexer/lexer.c b/Parser/lexer/lexer.c
index 4d10bccf0a53..0a078dd59414 100644
--- a/Parser/lexer/lexer.c
+++ b/Parser/lexer/lexer.c
@@ -1421,7 +1421,8 @@ f_string_middle:
                     return MAKE_TOKEN(
                         _PyTokenizer_syntaxerror(
                             tok,
-                            "f-string: newlines are not allowed in format specifiers for single quoted f-strings"
+                            "%c-string: newlines are not allowed in format specifiers for single quoted %c-strings",
+                            TOK_GET_STRING_PREFIX(tok), TOK_GET_STRING_PREFIX(tok)
                         )
                     );
                 }