class X:
    y = 1
    print([x + y for x in range(3)])

Python 3.12.0a7+ (heads/main:94f30c7557, May 10 2023, 17:27:39) [Clang 14.0.0 (clang-1400.0.29.202)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> class X:
...     y = 1
...     print([x + y for x in range(3)])
... 
[1, 2, 3]

>>> class X:
...     y = 1
...     print([x + y for x in range(3)])
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in X
  File "<stdin>", line 3, in <listcomp>
NameError: name 'y' is not defined