title: Change value of dictionary
body: <p>i'm trying to change a value of a dictionary.</p>
  
  <p>A pice of it look like</p>
  
  <pre><code>nuke_plugins_config = {'python_modules': '/dir/python_modules_v001', 'tools': '-/dir/tools_v001'}
  </code></pre>
  
  <p>Now if a use click a checkbox (QListwidgetitem, with checkbox) </p>
  
  <p>I want to change from <code>-/dir/</code> to <code>/dir/</code> if it's enabled or disabled.</p>
  
  <p>I tried it this way, witch was clearly wrong. </p>
  
  <pre><code>    if item.checkState() == 0:
          print self.nuke_plugins_config
          for key, value in self.nuke_plugins_config.iteritems():     
              if "-" in self.value_status[0]:
                  pass
              elif "" in self.value_status[0]:
                  value = "-/dir/{0}".format(self.value_status[1])
              print value
      elif item.checkState() == 2:
          print self.nuke_plugins_config
          for key, value in self.nuke_plugins_config.iteritems():     
              if "-" in self.value_status[0]:
                  pass
              elif "" in self.value_status[0]:
                  value = "/dir/{0}".format(self.value_status[1])
              print value 
  </code></pre>
  
  <p>Any suggestions, Thanks.</p>