map = Code("function () {"                                                                                                                                               
            "emit("                                                                                                                                                              
            "     {id: this.id, ip: this.ip }, {exists: 1}"                                                                                                                      
            "  );"                                                                                                                                                               
        "}")                                                                                                                                                                     
                                                                                                                                                                                 
reduce = Code("function (key, values) {"                                                                                                                                 
            "  var total = 0;"                                                                                                                                                   
            "  for (var i = 0; i < values.length; i++) {"                                                                                                                        
            "    total += 1;"                                                                                                                                                    
            "  }"                                                                                                                                                                
            "  return total;"                                                                                                                                                    
 "}")
results = mongo.map_reduce(map, reduce, "myresults")
print results.count()