count the number of word occurrence in given a file in Go

package main

import (
    "bufio"
    "fmt"
    "io"
    "log"
    "os"
    "strings"
)

func main() {
    file, err := os.Open("cars.txt")
    if err != nil {
        log.Fatalln(err)
    }
    defer file.Close()
    counts := wordCount(file)
    fmt.Println("Number of count is", counts["audi"])
}

func wordCount(rdr io.Reader) map[string]int {
    counts := map[string]int{}
    scanner := bufio.NewScanner(rdr)
    scanner.Split(bufio.ScanWords)
    for scanner.Scan() {
        word := scanner.Text()
        word = strings.ToLower(word)
        counts[word]++
    }
    return counts
}


Output: Number of count is 2