Fix assert in test and make error message more friendly

Author: TERESH1

Lib/test/test_ast/test_ast.py

@@ -823,8 +823,8 @@ def test_constant_as_name(self):
 
     def test_constant_as_unicode_name(self):
         for constant in b"Tru\xe1\xb5\x89", b"Fal\xc5\xbfe", b"N\xc2\xbane":
-            with self.assertRaises(ValueError,
-                msg="identifier must not be None, True or False after NFKC normalization"):
+            with self.assertRaisesRegex(ValueError,
+                "identifier must not be None, True or False after Unicode normalization \\(NKFC\\)"):
                 ast.parse(constant, mode="eval")
 
     def test_precedence_enum(self):

Parser/pegen.c

@@ -553,7 +553,7 @@ _PyPegen_new_identifier(Parser *p, const char *n)
         _PyUnicode_EqualToASCIIString(id, "True") ||
         _PyUnicode_EqualToASCIIString(id, "False"))
     {
-        PyErr_SetString(PyExc_ValueError, "identifier must not be None, True or False after NFKC normalization");
+        PyErr_SetString(PyExc_ValueError, "identifier must not be None, True or False after Unicode normalization (NKFC)");
         Py_DECREF(id);
         goto error;
     }