Need help in json parsing : I am getting data from api and i need to filter the array of dictionary based upon "total_price" tag, now the condition is i want only those flights whose price is between "35.0" to "55.0"

         {
                airline = 9W;
                "available_seats" = "<null>";
                bags =                 (
                );
                currency = USD;
                destination = 38551;
                origin = 39232;
                "price_details" =                 {
                };
                "rate_plan_code" = WIP;
                routes =                 (
                );
                taxes = "17.51";
                "total_price" = "31.7";
            }

As the total_price tag is coming as string i am not sure how to filter it using predicate etc. I need to filter the json response itself, no models were created for this api response. Please help