title: How do you invoke a function in a module which is in a package?
body: <p>I have a project structure of:</p>
  
  <pre><code>root_dir/
  └── app/
      ├── __init__.py
      ├── mymodule.py
  </code></pre>
  
  <p>inside of mymodule.py I have the following function:</p>
  
  <pre><code>def hello():
      print('hello world')
  </code></pre>
  
  <p>If i call python from inside the root directory I'd like to do the following:</p>
  
  <pre><code>&gt;&gt;&gt; import app
  &gt;&gt;&gt; app.mymodule.hello()
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  AttributeError: module 'app' has no attribute 'mymodule'
  </code></pre>
  
  <p>Is there anyway to invoke the hello function?</p>