title: What does vertical bar "|" (pipe) in function arguments type annotations mean?
body: <p>I came across function with signature like this:</p>
  <pre><code>def get_quantile(numbers: List[float], q: float | int ) -&gt; float | int | None :
  </code></pre>
  <p>What does it mean?</p>
  <p>It's a syntax error on my python 3.8. Do I need to import something from <code>future</code> to make it work?</p>