title: What is this attribute syntax in Python?
body: <p>I am current following <a href="https://pytorch.org/tutorials/beginner/pytorch_with_examples.html" rel="nofollow noreferrer">a tutorial in Pytorch</a> and there is this expression:</p>
  
  <pre><code>grad_h[h &lt; 0] = 0
  </code></pre>
  
  <p>How does this syntax work and what does it do?</p>