gh-127975: Avoid reusing quote types in ast.unparse if not needed (#127980)

1 files changed, 8 insertions, 3 deletions

diff --git a/Lib/ast.py b/Lib/ast.py
index 154d2c8..0937c27 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -1196,9 +1196,14 @@ class _Unparser(NodeVisitor):
                     fallback_to_repr = True
                     break
                 quote_types = new_quote_types
-            elif "\n" in value:
-                quote_types = [q for q in quote_types if q in _MULTI_QUOTES]
-                assert quote_types
+            else:
+                if "\n" in value:
+                    quote_types = [q for q in quote_types if q in _MULTI_QUOTES]
+                    assert quote_types
+
+                new_quote_types = [q for q in quote_types if q not in value]
+                if new_quote_types:
+                    quote_types = new_quote_types
             new_fstring_parts.append(value)
 
         if fallback_to_repr: