title: Strong typed python3.7 - return type and params are not failed
body: <p>I don't quite understand why this is not failing:</p>
  
  <pre><code>def hello(name: str) -&gt; int:
      ending:int = '!!!'
      return f'Hello {name} {ending}'
  
  print(hello('John')) # Hello John !!!
  </code></pre>
  
  <p>And if there is already possibility to strong type python?</p>