title: No module named '__main__.demo'; '__main__' is not a package python3
body: <p>If I execute <code>main.py</code> it works fine, the problem is when I execute <code>demo2.py</code></p>
  
  <pre><code>|myPackage
     |subPackage
        demo.py
        demo2.py
     main.py
  </code></pre>
  
  <p>main.py</p>
  
  <pre><code>from ludikDriver.demo2 import demo2_print
  
  demo2_print()
  </code></pre>
  
  <p>demo2.py</p>
  
  <pre><code>from .demo import demoprint
  
  def demo2_print():
      print("demo2")
      demoprint()
  
  demo2_print()
  </code></pre>
  
  <p>demo.py</p>
  
  <pre><code>def demoprint():
      print("demo")
  </code></pre>
  
  <p>Error: <code>from .demo import demoprint</code></p>
  
  <pre><code>ModuleNotFoundError: No module named '__main__.demo'; '__main__' is not a package
  </code></pre>
  
  <p>Should I have <code>__init__.py</code>?</p>