tf.shape() 和 x.get_shape().as_list()
https://blog.youkuaiyun.com/m0_37393514/article/details/82226754?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.compare&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.compare