I'm inordinately fond of using decorators for adding metadata attributes as markup on functions: def add_example(*args): def decorate(fn): if not h

I'm inordinately fond of using decorators for adding metadata attributes as markup on functions: def add_example(*args): def decorate(fn): if not hasattr(fn, 'examples'): fn.examples = [] fn.examples.insert(0, args) return fn return decorate I use decorators like this to add extra command-line options to methods, annotate what types to construct from a command-line string, add typed __doc__ extensions, note example input/output for unit testing and documentation, etc.