title: python pandas - dividing column by another column
body: <p>I'm trying to add a column to my <code>DataFrame</code> which is the product of division of two other columns, like so:</p>
  
  <pre><code>df['$/hour'] = df['$']/df['hours']
  </code></pre>
  
  <p>This works fine, but if the value in <code>['hours']</code> is less than <code>1</code>, then the <code>['$/hour']</code> value is greater than the value in <code>['$']</code>, which is not what I want.</p>
  
  <p>Is there a way of controlling the operation so that if <code>['hours'] &lt; 1</code> then <code>df['$/hour'] = df['$']</code>?</p>