It's interesting how differently two similar dynlangs, Python and Ruby, decided to offer meta-programming. Ruby decided to offer a very simple way of evaluating code at construction, but python has you define custom metaclasses. One sees it as a routine way of extending the language, and the other treats it as a 'black-art'.

Metaprogramming done wrong, no matter the mechanism, is very painful. So, I'm not sure which way is better.