Export contacts in Google Contacts as csv file, then add +86 for the phone numbers

GoogleContactsAdd+86.go

package main

import (
	"encoding/csv"
	"os"
	"strings"
)

func main() {
	file, err := os.Open("google.csv")
	if err != nil {
		panic(err)
	}
	defer file.Close()
	reader := csv.NewReader(file)
	reader.FieldsPerRecord = -1
	record, err := reader.ReadAll()
	if err != nil {
		panic(err)
	}

	// Writer
	Wfile, err := os.Create("contacts.csv")
	if err != nil {
		panic(err)
	}
	// Wfile.WriteString("\xEF\xBB\xBF")
	defer Wfile.Close()
	writer := csv.NewWriter(Wfile)
	for index, item := range record {
		// 36 38
		if index != 0 {
			item[36] = EditNum(item[36])
			item[38] = EditNum(item[38])
			item[27] = ""
		}
		writer.Write(item)
	}
	writer.Flush()
}

func EditNum(item string) string {
	if item == "" {
		return ""
	}
	t := strings.Split(item, ":::")
	var tels []string
	for _, tel := range t {
		if strings.HasPrefix(tel, "+86") || !strings.HasPrefix(tel, "+") || strings.HasPrefix(tel, "86") {
			if strings.HasPrefix(tel, "86") {
				tel = "+" + tel
			}
			tel = strings.Replace(tel, " ", "", -1)
			tel = strings.Replace(tel, "\u00a0", "", -1)
			tel = strings.Replace(tel, "-", "", -1)
			if !strings.HasPrefix(tel, "+") {
				tel = "+86" + tel
			}
			tel = tel[:3] + " " + tel[3:6] + " " + tel[6:10] + " " + tel[10:]
		}
		tels = append(tels, tel)
	}
	result := strings.Join(tels, " ::: ")
	return result
}