title: How to replace whitespaces with underscore?
body: <p>I want to replace whitespace with underscore in a string to create nice URLs. So that for example:</p>
  <pre><code>&quot;This should be connected&quot; 
  </code></pre>
  <p>Should become</p>
  <pre><code>&quot;This_should_be_connected&quot; 
  </code></pre>
  <p>I am using Python with Django. Can this be solved using regular expressions?</p>