My original question was too vague and was "closed as not constructive." As such, I will revise the question so that it caters to the answers that have already been posted. :-)

I am interested in the differences between Perl's Moose OO framework [Moose](http://moose.iinteractive.com/) and Python's stock OO framework. As a first point of comparison, how easy is it to create a simple class with a couple of attributes and a handful of methods?

Now, if this question gets reopened, I would also like to know: How easy is it to refactor code in the future if I decide to make an attribute "read only"? In other words, what steps would I have to take to change an attribute from being readable and writable to being read only? (I know, it's bad to change an API, but let's assume I'm working on something internally and realize in the middle of my implementation that an attribute really should be read-only.)