package importfunc import ( "bufio" "fmt" "math/rand" "os" ) func GenerateUserIdMap() { outfile, err := os.OpenFile("/Users/Caeru/dataprep/file/user_id_map.txt", os.O_WRONLY|os.O_CREATE, 0666) if err != nil { fmt.Printf("Open File Err : %v", err) } defer outfile.Close() writer := bufio.NewWriter(outfile) list := make([]int64, 0) for i := int64(1000000); i < 100000000; i++ { list = append(list, i) } rand.Shuffle(99000000, func(i, j int) { list[i], list[j] = list[j], list[i] }) for i := range list { outfile.WriteString(fmt.Sprintf("%v:%v\n", 1000000+i, list[i])) } writer.Flush() }