title: Unable to find definition of dict in python repo
body: <p>I'm not too good with Python, and I'm trying to find some source code associated with torchvision (<a href="https://github.com/pytorch/vision/tree/main/torchvision/" rel="nofollow noreferrer">https://github.com/pytorch/vision/tree/main/torchvision/</a>).</p>
  <p>I saw the following lines of code:</p>
  <pre><code>from torchvision.models import models
  models.__dict__[&quot;alexnet&quot;](first=True, second=False).eval()
  </code></pre>
  <p>I know that <code>torchvision.models</code> corresponds to this directory: <a href="https://github.com/pytorch/vision/tree/main/torchvision/models" rel="nofollow noreferrer">https://github.com/pytorch/vision/tree/main/torchvision/models</a></p>
  <p>But I am having trouble figuring out where <code>__dict__</code> is defined. It doesn't appear to be in the above directory after I tried to grep for its definition. Where or how can I find its definition?</p>