gh-99139: Improve NameError error suggestion for instances (#99140)

1 files changed, 21 insertions, 0 deletions

diff --git a/Doc/whatsnew/3.12.rst b/Doc/whatsnew/3.12.rst
index b6daa6d..fb28d67 100644
--- a/Doc/whatsnew/3.12.rst
+++ b/Doc/whatsnew/3.12.rst
@@ -75,6 +75,27 @@ Important deprecations, removals or restrictions:
 Improved Error Messages
 =======================
 
+* Improve the error suggestion for :exc:`NameError` exceptions for instances.
+  Now if a :exc:`NameError` is raised in a method and the instance has an
+  attribute that's exactly equal to the name in the exception, the suggestion
+  will include ``self.<NAME>`` instead of the closest match in the method
+  scope. Contributed by Pablo Galindo in :gh:`99139`.
+
+    >>> class A:
+    ...    def __init__(self):
+    ...        self.blech = 1
+    ...
+    ...    def foo(self):
+    ...        somethin = blech
+
+    >>> A().foo()
+    Traceback (most recent call last):
+      File "<stdin>", line 1
+        somethin = blech
+                   ^^^^^
+    NameError: name 'blech' is not defined. Did you mean: 'self.blech'?
+
+
 * Improve the :exc:`SyntaxError` error message when the user types ``import x
   from y`` instead of ``from y import x``. Contributed by Pablo Galindo in :gh:`98931`.