Ian Lee <ianlee1...@gmail.com> added the comment:
@sobolevn - Hmm, interesting.. I tested in python 3.9 which I had available, and I can reproduce your result, but I think it's different because you are using a tuple. If I use a list then I see my same reported behavior in 3.9: ```python Python 3.9.10 (main, Jan 26 2022, 20:56:53) [GCC 10.2.1 20210110] on linux Type "help", "copyright", "credits" or "license" for more information. >>> class A: ... __slots__ = ('x',) ... >>> a = A() >>> a.__slots__ ('x',) >>> a.__slots__ += ('y',) Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'A' object attribute '__slots__' is read-only >>> a.__slots__ ('x',) >>> >>> >>> >>> class B: ... __slots__ = ['x'] ... >>> b = B() >>> b.__slots__ ['x'] >>> b.__slots__ += ['y'] Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'B' object attribute '__slots__' is read-only >>> b.__slots__ ['x', 'y'] ``` ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue46550> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com