title: Output None in function
body: <p>why here the output of <code>my_func</code> is None? I assign an integer to <code>x</code> then I have an expression in local scope.</p>
  
  <pre><code>Def my_func():
         x=4
         x**2
  Print(my_func())
  </code></pre>
  
  <p>Output: <code>None</code></p>