title: from __future__ import annotations
body: <p><a href="https://docs.python.org/3/library/__future__.html" rel="noreferrer">Python doc <code>__future__</code></a></p>
  <p>In python doc about <code>__future__</code> there is a table below where it shows that
  annotations &quot;optional in&quot; 3.7.0b1 and &quot;mandatory in&quot; 4.0
  but i am still able to use annotations in 3.8.2 without importing annotations then what is the use of it.</p>
  <pre><code>&gt;&gt;&gt; def add_int(a:int, b:int) -&gt; int:
  ...     return a + b
  &gt;&gt;&gt; add_int.__annotations__
  {'a': &lt;class 'int'&gt;, 'b': &lt;class 'int'&gt;, 'return': &lt;class 'int'&gt;}
  </code></pre>
  <p>I doubt I don't clearly understand the meaning of &quot;optional in&quot; and &quot;mandatory in&quot; here</p>