I recently read an entry by someone whowas surprised that Python subclasses did not automatically call theirparent class's 'constructor' method, by which he meant __init__ .This is a straightforward consequence of Python's inheritance model,but Python's inheritance model is slightly odd.

The straightforward way to explain Python's inheritance model is thatit uses what I could call 'lookup based' or 'name based' subclassing,where what subclassing does is change what binding will be returned when

One enduringly popular model for blogging engines is that entries willbe files in the filesystem, and the blog engine will just wrap themup in various simple ways. This approach has a clear and attractivesimplicity and thus an obvious appeal, but as I have found out fromfollowing this route myself this simplicity hides a number of subtle problems .

All of the problems can be summarized in one word: metadata . Blogentries have (or need) quite a lot of of metadata associated with them,and making files your entries