Richard Jones' Log: Using "dict" as a base class

Here's a relatively trivial example of using dict as a base class to create a dict that returns True or False on item accesses as if has_key() was called:

class TruthDict(dict):
    def __getitem__(self, key):
        return self.has_key(key)

I use this in Zope code(*) to make a simple var that I can shove various strings into and later test for the existence of an arbitrary string. Why not use has_key()? Because with this code I can perform tests using simpler ZPT path expressions instead of having to use python expressions.

*: of course, being a Zope object used in templating, there's an additional class var __allow_access_to_unprotected_subobjects__ = 1 (yeah, old school Zope) that I've omitted from the example code to make it more readable.

... just thought I'd let everyone know I was still alive. Just very busy with work and Roundup :)