title: What does "import" prefer - .pyd (.so) or .py?
body: <p>I have 2 files in same directory, a compiled library file and source file:</p>
  
  <pre><code>.
  ├── a.py
  └── a.pyd
  </code></pre>
  
  <p>It looks like <code>import a</code> that actually imports the <code>a.pyd</code> module. But I can't find some official document guaranteeing that.</p>
  
  <p>Does any one know about the import ordering of different file type?</p>
  
  <p>This same question applies to Unix Python extensions (.so)</p>