You're right. I am thinking implementing 4 sequence methods
(contains/len/iter/getitem) and set a depraction warning for them. We can
remove this methods in next relase

On Sun, May 19, 2019, 2:37 PM Eric V. Smith <report@bugs.python.org> wrote:

>
> Eric V. Smith <eric@trueblade.com> added the comment:
>
> Unfortunately your change isn't backward compatible with the existing
> (namedtuple) version.
>
> I expect this to fail in the dataclass version:
> >>> finder, name, ispkg = list(pkgutil.iter_modules(None))[0]
>
> And since this is an enhancement, it can only go in to 3.8. And the window
> is closing for that, so it's more likely to be 3.9, if we decide that
> backward compatibility isn't important here.
>
> ----------
> nosy: +eric.smith
> type:  -> enhancement
> versions:  -Python 3.6, Python 3.7
>
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> <https://bugs.python.org/issue36962>
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