title: What does this warning mean? "not declared in __all__"
body: <p>Pycharm is giving me a warning that I don't know how to fix. </p>
  
  <p><a href="https://i.stack.imgur.com/2rZrf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2rZrf.png" alt="enter image description here"></a></p>
  
  <p>So what is the wrong practice that I engaged in when coding? how can I fix this?</p>