title: How to define an alias for a type in Python for type hinting
body: <p>How to define an alias for a type to use type hint:</p>
  
  <pre><code>import typing
  type Ticker str # How to do this? I used golang notation. How do you do it in python?
  Report = typing.Dict[Ticker, typing.List] 
  </code></pre>
  
  <p>Which means Ticker is a type of string and Report is a dict from Ticker to a list. Thank you. 
  The good thing about this aliasing is that anyone knows that it is a ticker. Much clear and more readable than writing Report = typing.Dict[str, typing.List]</p>