Oct. 5, 2001
5:07 p.m.
Yes, I'm sure: we need a PEP first. Ideally it would answer some of the questions raised above, and it would lay out the class hierarchy.
The more I think about this, the more I agree that we need a PEP first: there are lots of potential traps. Maybe the biggest danger: declaring an abstract base class for e.g. "sequence-ness" would encourage programmers to test isinstance(x, sequencebase) when all they *really* need is something that supports the __getitem__ protocol. This would encourage writing code that is less polymorphic than it could be, and that would be a real loss. --Guido van Rossum (home page: http://www.python.org/~guido/)