title: What is the purpose of using " -> int" after a function def in Python?
body: <pre><code>def romanToInt(self, s: str) -&gt; int
  </code></pre>
  
  <p>This is function name and  this format is used in python. I am confused why we are using this arrow and why we are using <code>int</code> inside paranthesis after <code>s</code>. Can someone explain please?</p>