Issue 41285: memoryview does not support subclassing

Currently memoryview does not support subclassing:

>>> class B(memoryview): pass
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: type 'memoryview' is not an acceptable base type


Subclassing memoryview can be useful when
- class A supports the buffer protocol;
- class B wraps class A and should support the buffer protocol provided by class A;
- class A does not support subclassing.

In this situation,

class B(memoryview):
    def __new__(cls, a):
        return super(B, cls).__new__(cls, a)

where a is an instance of class A, would let instances of B support the buffer protocol provided by a.


Is there any particular reason why memoryview does not support subclassing?

Would you be more specific about why you need that feature on the Python-ideas mailing list or "Ideas" category on discuss.python.org?

Thank you, I have posted an explanation in the "Ideas" category of discuss.python.org.

If I understand this correctly, I think this may be a duplicate of #13797.


Something like a __getbuffer__ protocol would be needed. I'm not
saying we *should* go that route, just stating the requirements
from my perspective.

You are correct, this is indeed a duplicate of #13797. My apologies for not finding this issue before opening a new one. If there are no objections, I will close this issue as a duplicate.

Yes, let's make #13797 a superseder.