Make some styling changes.

Try to fit C code in reasonable width

Author: Tapeline

Lib/test/test_scope.py

@@ -836,26 +836,20 @@ def g(self, __arg):
             closure(_MultiplyNested__arg=2)
 
     def test_builtin_deletion_err_message(self):
-        with self.assertRaisesRegex(
-            NameError, "cannot delete builtin 'all'"
-        ):
+        with self.assertRaisesRegex(NameError, "cannot delete builtin 'all'"):
             del all
 
         def f():
             del all
 
-        with self.assertRaisesRegex(
-            UnboundLocalError, "cannot delete builtin 'all'"
-        ):
+        with self.assertRaisesRegex(UnboundLocalError, "cannot delete builtin 'all'"):
             f()
 
         def g():
             global all
             del all
 
-        with self.assertRaisesRegex(
-            NameError, "cannot delete builtin 'all'"
-        ):
+        with self.assertRaisesRegex(NameError, "cannot delete builtin 'all'"):
             g()
 
 

Misc/NEWS.d/next/Core_and_Builtins/2025-09-18-01-13-22.gh-issue-138890.x2QKfy.rst

@@ -1 +1 @@
-Deleting builtin names with ``del`` now gives a clearer error message.
+Deleting built-in names with :keyword:`del` now gives a clearer error message.

Python/bytecodes.c

@@ -1577,10 +1577,13 @@ dummy_func(
             err = PyObject_DelItem(ns, name);
             // Can't use ERROR_IF here.
             if (err != 0) {
-                const char *err_msg = PyMapping_HasKey(BUILTINS(), name)
-                        ? CANNOT_DELETE_BUILTIN_ERROR_MSG
-                        : NAME_ERROR_MSG;
-                _PyEval_FormatExcCheckArg(tstate, PyExc_NameError, err_msg, name);
+                if (PyMapping_HasKeyWithError(BUILTINS(), name) == 1) {
+                    _PyEval_FormatExcCheckArg(tstate, PyExc_NameError,
+                                              CANNOT_DELETE_BUILTIN_ERROR_MSG, name);
+                } else {
+                    _PyEval_FormatExcCheckArg(tstate, PyExc_NameError,
+                                              NAME_ERROR_MSG, name);
+                }
                 ERROR_NO_POP();
             }
         }
@@ -1721,11 +1724,13 @@ dummy_func(
                 ERROR_NO_POP();
             }
             if (err == 0) {
-                const char *err_msg = PyMapping_HasKey(BUILTINS(), name)
-                                      ? CANNOT_DELETE_BUILTIN_ERROR_MSG
-                                      : NAME_ERROR_MSG;
-                _PyEval_FormatExcCheckArg(tstate, PyExc_NameError,
-                                          err_msg, name);
+                if (PyMapping_HasKeyWithError(BUILTINS(), name) == 1) {
+                    _PyEval_FormatExcCheckArg(tstate, PyExc_NameError,
+                                              CANNOT_DELETE_BUILTIN_ERROR_MSG, name);
+                } else {
+                    _PyEval_FormatExcCheckArg(tstate, PyExc_NameError,
+                                              NAME_ERROR_MSG, name);
+                }
                 ERROR_NO_POP();
             }
         }
@@ -1892,13 +1897,15 @@ dummy_func(
         inst(DELETE_FAST, (--)) {
             _PyStackRef v = GETLOCAL(oparg);
             if (PyStackRef_IsNull(v)) {
-                PyObject *name;
-                name = PyTuple_GetItem(_PyFrame_GetCode(frame)->co_localsplusnames,
-                                       oparg);
-                const char *err_msg = PyMapping_HasKey(BUILTINS(), name)
-                                      ? CANNOT_DELETE_BUILTIN_ERROR_MSG
-                                      : UNBOUNDLOCAL_ERROR_MSG;
-                _PyEval_FormatExcCheckArg(tstate, PyExc_UnboundLocalError, err_msg, name);
+                PyObject *localsplusnames = _PyFrame_GetCode(frame)->co_localsplusnames;
+                PyObject *name = PyTuple_GetItem(localsplusnames, oparg);
+                if (PyMapping_HasKeyWithError(BUILTINS(), name) == 1) {
+                    _PyEval_FormatExcCheckArg(tstate, PyExc_UnboundLocalError,
+                                              CANNOT_DELETE_BUILTIN_ERROR_MSG, name);
+                } else {
+                    _PyEval_FormatExcCheckArg(tstate, PyExc_UnboundLocalError,
+                                              UNBOUNDLOCAL_ERROR_MSG, name);
+                }
                 ERROR_IF(true);
             }
             _PyStackRef tmp = GETLOCAL(oparg);