Map and sort data

main.go

package main

import (
	"encoding/csv"
	"log"
	"os"
	"sort"
	"strconv"
)

type Data struct {
	Key   string
	Value float64
}

type DataList []Data

func (d DataList) Len() int {
	return len(d)
}

func (d DataList) Swap(i, j int) {
	d[i], d[j] = d[j], d[i]
}

func (d DataList) Less(i, j int) bool {
	return d[i].Value < d[j].Value
}

func mapData(gameNames []string, sales []float64) DataList {
	dataMap := map[string]float64{}
	for index, value := range gameNames {
		dataMap[value] = sales[index]
	}
	data := make(DataList, len(dataMap))
	iterator := 0
	for k, v := range dataMap {
		data[iterator] = Data{k, v}
		iterator++
	}
	sort.Sort(sort.Reverse(data))
	return data
}