> Raymond has resisted adding a base class to namedtuple. I believe the
> preferred way to identify a namedtuple is to look for a _fields member.

FWIW, that was also Guido's opinion as well.  A named tuple is generic concept defined in the glossary as "Any tuple-like class whose indexable elements are also accessible using a named attribute".  This includes user-defined classes, classes created by collections.namedtuple, and instances of structseq.  The code generated by oollections.namedtuple was based on patterns already in widespread use at the time.