human
I wrote the below code

    global register_option, get_option, set_option, reset_option
    def wrap(func):
        def inner(key, *args, **kwds):
            pkey = ('%s.%s' % (prefix, key))
            return func(pkey, *args, **kwds)
        return inner
    _register_option = register_option
    _get_option = get_option
    _set_option = set_option
    set_option = wrap(set_option)
    get_option = wrap(get_option)
    register_option = wrap(register_option)
    (yield None)
    set_option = _set_option
    get_option = _get_option
    register_option = _register_option

What's a good function header?
assistant
#Here's a good function header.

@contextmanager
def config_prefix(prefix):