paginator.py 文件源码

def __init_subclass__(cls, **kwargs):
        super().__init_subclass__(**kwargs)
        cls._reaction_map = OrderedDict()
        _suppressed_methods = set()
        # We can't use inspect.getmembers because it returns the members in
        # lexographical order, rather than definition order.
        for name, member in itertools.chain.from_iterable(b.__dict__.items() for b in cls.__mro__):
            if name.startswith('_'):
                continue

            # Support for using functools.partialmethod as a means of simplifying pages.
            is_callable = callable(member) or isinstance(member, functools.partialmethod)

            # Support suppressing page methods by assigning them to None
            if not (member is None or is_callable):
                continue

            # Let sub-classes override the current methods.
            if name in cls._reaction_map.values():
                continue

            # Let subclasses suppress page methods.
            if name in _suppressed_methods:
                continue

            if member is None:
                _suppressed_methods.add(name)
                continue

            emoji = getattr(member, '__reaction_emoji__', None)
            if emoji:
                cls._reaction_map[emoji] = name
                _log.debug('Initializing emoji %s for method %s in class %s',
                           hex(ord(emoji)), member.__qualname__, cls.__name__)

        # We need to move stop to the end (assuming it exists).
        # Otherwise it will show up somewhere in the middle
        with contextlib.suppress(StopIteration):
            key = next(k for k, v in cls._reaction_map.items() if v == 'stop')
            cls._reaction_map.move_to_end(key)