':return: é®é¢æå±è¯é¢
:rtype: Topic.Iterable'

@property
@check_soup('_topics')
def topics(self):

    from .topic import Topic
    for topic in self.soup.find_all('a', class_='zm-item-tag'):
        (yield Topic((Zhihu_URL + topic['href']), topic.text.replace('\n', ''), session=self._session))
