Change default message for NameError to "name '...' is not defined"

Co-authored-by: Aaron Wieczorek <aaronw@fastmail.com>

Author: johnslavik

Lib/test/test_exceptions.py

@@ -2020,7 +2020,7 @@ def f():
                 sys.__excepthook__(*sys.exc_info())
 
         # 'spam' should appear even when message was empty.
-        self.assertIn("'spam'", err.getvalue())
+        self.assertIn("name 'spam' is not defined", err.getvalue())
 
     # Note: name suggestion tests live in `test_traceback`.
 

Lib/test/test_traceback.py

@@ -4942,8 +4942,8 @@ def func():
                 exc.args = ()
                 raise
         actual = self.get_suggestion(func)
-        self.assertIn("'spam'", actual)
-        self.assertIn("'span'?", actual)
+        self.assertIn("name 'spam' is not defined", actual)
+        self.assertIn("Did you mean: 'span'?", actual)
 
 
 class PurePythonSuggestionFormattingTests(

Lib/traceback.py

@@ -1133,7 +1133,7 @@ def __init__(self, exc_type, exc_value, exc_traceback, *, limit=None,
                         obj_type_name = object.__getattribute__(obj_type, "__name__")
                         self._str = f"{obj_type_name!r} object has no attribute {wrong_name!r}"
                 else:  # NameError
-                    self._str = repr(wrong_name)
+                    self._str = f"name {wrong_name!r} is not defined"
             if suggestion:
                 self._str += f". Did you mean: '{suggestion}'?"
             if issubclass(exc_type, NameError):