title: Determining whether an value is a whole number in Python
body: <p>I would like to determine if a numeric value in Python is a whole number. For example, given: </p>
  
  <pre><code>y = x / 3
  </code></pre>
  
  <p>I want to distinguish between values of <code>x</code> which are evenly divisible by 3 those which are not.</p>