How to set name of user water level in python API?

waterlevel_s = g_i.waterlevel((-50,self.WaterLevelLeft), (0,self.WaterLevelLeft))
 
I have a water level as can be seen above. I would like to give it a name so I can retrieve it later. I have tried "waterlevel_s.Name = "WL_Left_" + self.WaterLevelLeft", but to no avail.