From: "Armin Ronacher" <armin.ronacher@active-4.com>
There are far more responses for that topic than I imagined so I would love to write a PEP about that topic, incorporating the ideas/questions and suggestions discussed here.
Instead of going straight to a PEP, I recommend opening a new wiki page on the topic, letting people post sample pure python implementations, pros/cons of various APIs, showing sample use cases, and analyzing the O(n) behavior of various implementation strategies. As a reference point, the collections.namedtuple() recipe was much simpler but took over six months to mature. Its development process started by combining the best of all previously posted attempts at the same thing, then it was exercised heavily in real apps, then it was posted on ASPN and underwent significant improvements based on feedback from a number of expert developers. Then, it was proposed on python-dev and improved again based on feedback received there. Upon writing the docs and creating examples, more refinements ensued. Upon applying it to the standard library, more was learned. After the alpha, we started getting user feedback and it got refined even further. Raymond