This is meant to replace my proposal in #30020 to change attrgetter to use namedtuple.  By creating a new function implemented in Python, I avoid making changes to the existing attrgetter, which means that both the need of implementing a C version and the risk of changing the performance or other characteristics of the existing function are eliminated.

My suggestion is to put this in the collections module next to namedtuple.  This eliminates the circular import problem and is a natural fit as it is an application of namedtuple.