title: Calling returned function results in "object is not callable" error
body: <pre><code>def hello_decorator(func):
  
      def inner():
          print('hello,this is before function execution')
          func()
          print('this is after function execution')
  
      return inner()
  
  def hello():
      print('hello user')
  
  hello = hello_decorator(hello)
  
  hello()
  </code></pre>
  <p>add i got this error:</p>
  <pre><code>Traceback (most recent call last):
    File &quot;C:/Users/se7en/Desktop/codeyad/pythonProject/p3.py&quot;, line 15, in &lt;module&gt;
      hello()
  TypeError: 'NoneType' object is not callable
  </code></pre>