code: def _api_itemvalue(self, plugin, item, value=None, history=False, nb=0):
          
          response.content_type = 'application/json; charset=utf-8'
  
          if plugin not in self.plugins_list:
              abort(400, "Unknown plugin %s (available plugins: %s)" % (plugin, self.plugins_list))
  
          # Update the stat
          self.__update__()
  
          if value is None:
              if history:
                  ret = self.stats.get_plugin(plugin).get_stats_history(item, nb=int(nb))
              else:
                  ret = self.stats.get_plugin(plugin).get_stats_item(item)
  
              if ret is None:
                  abort(404, "Cannot get item %s%s in plugin %s" % (item, 'history ' if history else '', plugin))
          else:
              if history:
                  # Not available
                  ret = None
              else:
                  ret = self.stats.get_plugin(plugin).get_stats_value(item, value)
  
              if ret is None:
                  abort(404, "Cannot get item %s(%s=%s) in plugin %s" % ('history ' if history else '', item, value, plugin))
  
          return ret
docs: Father method for _api_item and _api_value.