title: How to pad a irregular shape tensor in tensorflow (pure TF way)?
body: <pre><code>test_tensor = [[2], [1, 2, 3], [4, 5]] # irregular shape
  # dose there have a tf (better, and faster?) function to pad this tensor to a dense tensor with a defult value?
  # like this: test_tensor ==&gt; dense tensor:[[2, -1, -1],[1, 2, 3], [4, 5, -1]]
  </code></pre>
  
  <p>Ps. Please do not use pure python &amp; numpy  </p>
  
  <p>Because I need add this operation into my TF model graph, so maybe need complete the operation with <strong>pure TF way?</strong> </p>