I know dataset has output\_shapes, but it shows like below:

> 
> data\_set: DatasetV1Adapter shapes: {item\_id\_hist: (?, ?), tags: (?, ?), client\_platform: (?,), entrance: (?,), item\_id: (?,), lable: (?,), mode: (?,), time: (?,), user\_id: (?,)}, types: {item\_id\_hist: tf.int64, tags: tf.int64, client\_platform: tf.string, entrance: tf.string, item\_id: tf.int64, lable: tf.int64, mode: tf.int64, time: tf.int64, user\_id: tf.int64}
> 
> 
> 

How can I get the total number of my data?