From: "andrew cooke" <andrew@...>
Date: Sat, 31 May 2008 09:34:38 -0400 (CLT)
ABCs are "Abstract Base Classes" and are a way of describing interfaces while keeping some kind of "duck typing". They're described at http://www.python.org/dev/peps/pep-3119/ However, they don't seem that useful at first - the most obvious use for them that I could see was to write unit tests that verify types (although they are more complex than I first thought - see all the details in the link above). Things become much clearer, once you realise that Python will have optional typing. See http://www.artima.com/weblogs/viewpost.jsp?thread=89161 - then it's easy to see how the ABCs will be used in type constraints. Andrew