title: i have made an module to add two integer, but calling it gives me "none" answer
body: <p>I'm beginner and learning to code,</p>
  <p>Here is Module:</p>
  <pre><code>class extfile:
      def add(x, y):
          return x + y
  </code></pre>
  <p>Here is the Program:</p>
  <pre><code>class A:
      def a(x, y):
          extfile.add(x,y)    
  print(A.a(4,5))
  </code></pre>
  <p>Here is the Output:</p>
  <blockquote>
  <p>None</p>
  </blockquote>