title: Does python optimize modules when they are imported multiple times?
body: <p>If a large module is loaded by some submodule of your code, is there any benefit to referencing the module from that namespace instead of importing it again?</p>
  
  <p>For example:
  I have a module MyLib, which makes extensive use of ReallyBigLib. If I have code that imports MyLib, should I dig the module out like so</p>
  
  <pre><code>import MyLib
  ReallyBigLib = MyLib.SomeModule.ReallyBigLib
  </code></pre>
  
  <p>or just</p>
  
  <pre><code>import MyLib
  import ReallyBigLib
  </code></pre>