title: Convert dense tensor to ragged tensor
body: <p>I have a Sparse Tensor which I converted into Dense Tensor. After converting from sparse to dense using <code>tf.sparse.to_dense</code>, I got an output which looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/3Uklm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3Uklm.png" alt="Dense tensor"></a></p>
  
  <p>I want to remove default values i.e zero and convert it to ragged tensor like this:
  <a href="https://i.stack.imgur.com/GPO34.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GPO34.png" alt="Ragged tensor"></a>
  <strong>Data in the above two images is different</strong><br>
  <br>
  I went through Tensorflow documentation and I am unable to find any method to do this. I tried using <code>boolean_mask</code>, the major problem is to compute <code>boolean_mask</code> for each row individually.<br>
  So, I am wondering if there is an efficient way to achieve this.</p>
  
  <p>Thank you.</p>