register_methods.py

# Test on delivery

def register(key):
    def decorator(method):
        method.response = key
        return method
    return decorator


@register('$')
def msgtype_DOLLARSIGN(self, blah):
    pass


class Whatever(object):

    def __init__(self):
        self.registry = {}
        for x in (getattr(self, k) for k in dir(self)):
            if callable(x) and hasattr(x, 'response'):
                self.registry.update({getattr(x, 'response'): x})