Bug report

Bug description:

_SelectorDatagramTransport defines a class-level _buffer_factory attribute: 

class _SelectorDatagramTransport(_SelectorTransport, transports.DatagramTransport):
    _buffer_factory = collections.deque
    _header_size = 8

This attribute is never used anywhere in CPython. A project-wide search for _buffer_factory returns only this line.

Proposed change:

Drop the dead attribute:

class _SelectorDatagramTransport(_SelectorTransport, transports.DatagramTransport):
    _header_size = 8

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

Linked PRs

• gh-150486: Remove dead _buffer_factory attribute from _SelectorDatagramTransport #150487