Simple way of implementing before and after filters in a web.py app

controller.py

def before_filter(*args, **kwargs):
    print "before"

def after_filter(*args, **kwargs):
    print "after"

class Controller(object)
    @RequestFilter(before=[before_filter], after=[after_filter])
    def GET(self):
        return "Hello!"
        

request_filter.py

from functools import update_wrapper

class RequestFilter(object):
    def __init__(self, before=[], after=[], **kwargs):
        self.before = before
        self.after = after

    def __call__(self, function):
        def wrapper(request, *args, **kwargs):
            for b in self.before:
                b(*args, **kwargs)
            result = function(request, *args, **kwargs)
            for a in self.after:
                a(*args, **kwargs)
            return result
        update_wrapper(wrapper, function)
        return wrapper