title: What is the for loop trying to achieve
body: <p>This probably is very simple but can someone explain what the below is meant to achieve?</p>
  
  <pre><code>def clean_param_value(self, value):
      for s, r in (('&lt;', '{'), ('&gt;', '}'), (' ', '_')):
          value.replace(s, r)
  </code></pre>
  
  <p>It is called from </p>
  
  <pre><code>    params = dict(
          (item['ParameterName'],
           self.clean_param_value(item['ParameterValue']))
          for item in cursor.fetchall()
          )
  </code></pre>
  
  <p>In the <code>for</code> loop are the variables <code>s</code> and <code>r</code> assigned to <code>'&lt;'</code> and <code>'{'</code> respectively and a <code>replace</code> is performed on the value field? Followed by the other two sets in <code>for</code> loop.</p>