fix bug: set(None)
fix bug: set(None)

alone-walker/BlogSpider,hack4code/BlogSpider,alone-walker/BlogSpider,wartalker/BlogSpider,wartalker/BlogSpider,hack4code/BlogSpider,alone-walker/BlogSpider,wartalker/BlogSpider,hack4code/BlogSpider,hack4code/BlogSpider,wartalker/BlogSpider,alone-walker/BlogSpider