title: Python imported module dependency
body: <p>Let's say I have file main.py :</p>
  
  <pre><code>import math
  import mymodule.py
  print(math.ceil(5/3))
  </code></pre>
  
  <p>and then mymodule.py :</p>
  
  <pre><code>print(math.ceil(10/3))
  </code></pre>
  
  <p>mymodule.py gives an error that math is not defined, even though its parent module has it imported.</p>
  
  <p>Considering <strong>both</strong> <code>main.py</code> and <code>mymodule.py</code> need to use the <code>math</code> lib, do I need to import it twice? It just seems non-optimal. What's the most pythonic way to solve this issue?</p>
  
  <p>I know it's a dumb example, but I'm trying to fragment a code I made into several modules for organization, and this issue appeared multiple times in several levels</p>