I think this goes too far because it's not realistic to expect type checkers to support arbitrary base classes on NamedTuple. Also, there haven't been any user requests that I can see for multiple inheritance with anything other than Generic. So I'd prefer to merge the other PR that allows multiple inheritance with Generic only.

I also think it makes sense to only allow multiple inheritance withGeneric, for now. It's a smaller change; and, there should be opportunity to rethink it in the future if it turns out that people really need arbitrary multiple inheritance for whatever reason.

So, let's just close this?

Thank you@AlexWaygood and@gvanrossum. Updated to 3.14 and applied the suggestions.

I'm OK with this given the discussion on the issue; will take another look at the code soon.

Reminder for this: the 3.14 beta freeze is in two weeks.

I found

>>>from typingimport NamedTuple......classFoo(NamedTuple):...     x:int......classBar(NamedTuple,Foo):...     y:int

which fails with

Traceback (most recent call last):  File "<python-input-1>", line 6, in <module>    class Bar(NamedTuple, Foo):        y: int  File "/home/bswck/Python/cpython/Lib/typing.py", line 2938, in __new__    nm_tpl.__bases__ = bases    ^^^^^^^^^^^^^^^^TypeError: Cannot create a consistent method resolution order (MRO) for bases tuple, Foo

Traceback (most recent call last):  File "<python-input-1>", line 6, in <module>    class Bar(NamedTuple, Foo):        y: int  File "/home/bswck/Python/cpython/Lib/typing.py", line 2902, in __new__    raise TypeError(        'can only inherit from a NamedTuple type and Generic')TypeError: can only inherit from a NamedTuple type and Generic

If we swap the order of bases, with multiple inheritance the error won't happen

>>>classBar2(Foo,NamedTuple):...     y:int

and the result may be surprising

>>>import inspect... inspect.signature(Bar2)<Signature (y: int)>

My suggestion is to reiteratepython/typing#427 (please checkhttps://github.com/bswck/make-typed-namedtuples-final!) and explicitly prohibit the inheritance of typed namedtuples.