Render REPL error overlays in red without a prefix

Author: johnslavik

Lib/_pyrepl/reader.py

@@ -288,7 +288,6 @@ class Reader:
     ps3: str = "|.. "
     ps4: str = R"\__ "
     kill_ring: list[list[str]] = field(default_factory=list)
-    error_prefix: str = "! "
     msg: str = ""
     arg: int | None = None
     finished: bool = False
@@ -883,12 +882,11 @@ def debug(self, msg: str) -> None:
         pass
 
     def error(self, msg: str = "none") -> None:
-        error_prefix = self.error_prefix
         if self.can_colorize:
-            t = THEME()
-            error_prefix = f"{t.error}{error_prefix}{t.reset}"
+            colors = _colorize.ANSIColors
+            msg = f"{colors.RED}{msg}{colors.RESET}"
         self.console.beep()
-        self.msg = error_prefix + msg
+        self.msg = msg
         self.invalidate_message()
 
     def update_screen(self) -> None:

Lib/test/test_pyrepl/test_reader.py

@@ -14,7 +14,7 @@
 from _pyrepl.layout import LayoutMap
 from _pyrepl.readline import ReadlineAlikeReader, ReadlineConfig
 from _pyrepl.reader import Reader
-from _colorize import default_theme
+from _colorize import ANSIColors, default_theme
 
 
 overrides = {"reset": "z", "soft_keyword": "K"}
@@ -467,11 +467,11 @@ def test_colorized_error_message(self):
 
         reader.handle1()
 
-        theme = default_theme.syntax
         self.assertEqual(
             reader.msg,
-            f"{theme.error}! {theme.reset}nothing to yank",
+            f"{ANSIColors.RED}nothing to yank{ANSIColors.RESET}",
         )
+        self.assertEqual(reader.screen[-1], reader.msg)
 
     def _test_error_message(
         self,
@@ -490,8 +490,8 @@ def _test_error_message(
         while not reader.msg:
             reader.handle1()
 
-        self.assertEqual(reader.msg, f"! {expected}")
-        self.assertEqual(reader.screen[-1], f"! {expected}")
+        self.assertEqual(reader.msg, expected)
+        self.assertEqual(reader.screen[-1], expected)
         console.beep.assert_called_once()
 
     def test_invalid_key_message(self):

Misc/NEWS.d/next/Library/2026-10-20-20-00-00.gh-issue-148228.X7mQp2.rst

@@ -0,0 +1,2 @@
+Display error overlays in the new interactive shell without the ``!`` prefix
+and in non-bold red when color is enabled. Patch by Bartosz Sławecki.