Ian Bicking: the old part of his blog

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I've had a lot of fun with Io, a prototype-oriented language that reminds me of Self on its good days; I would love to use a more prototype-based metaphor for programming in Python, but Python really hasn't had any good facilities for writing anonymous functions for assignment. This makes it difficult to incrementally expand the functionality of a prototype.

Simply copying the dictionary from one object to another also won't permit a derived instance from picking up the addition of new attributes to its prototype. An override of the getattr method that would check the local dictionary for an item, then proceed to checking the prototype, would be a bit better for this.
Comment on Self and Prototype-based Programming
by Scott Dunlop