>>> '+'.join('1234')'1+2+3+4'>>> '+'.join(a for a in '1234')'1+2+3+4'>>> '+'.join(a for a in '1234' if a=='2')'2'>>> '+'.join(sorted('4+2+1+3'[::2]))'1+2+3+4'
posted on 2017-04-06 17:40 震撼起飞 阅读(1726) 评论(0) 编辑 收藏 举报
