代码如下，引入了正则表达式的使用：

package main

import (
	"fmt"
	"io"
	"net/http"
	"os"
	"regexp"
	"strconv"
)

func savToFile(index int, filmName, filmScore [][]string) {
	f, err := os.Create("第" + strconv.Itoa(index) + "页.txt")
	if err != nil {
		fmt.Println("os create err", err)
		return
	}
	defer f.Close()
	// 查出有多少条
	n := len(filmName)
	// 先写抬头 名称     评分
	f.WriteString("电影名称" + "\t\t\t" + "评分" + "\n")
	for i := 0; i < n; i++ {
		f.WriteString(filmName[i][1] + "\t\t\t" + filmScore[i][1] + "\n")
	}
}

func main() {
	var start, end int
	fmt.Print("请输入要爬取的起始页")
	fmt.Scan(&start)
	fmt.Print("请输入要爬取的终止页")
	fmt.Scan(&end)
	working(start, end)
}

func working(start int, end int) {
	fmt.Printf("正在爬取%d到%d页", start, end)
	for i := start; i <= end; i++ {
		SpiderPage(i)
	}
}

// 爬取一个豆瓣页面数据信息保存到文档
func SpiderPage(index int) {
	// 获取url
	url := "https://movie.douban.com/top250?start=" + strconv.Itoa((index-1)*25) + "&filter="

	// 爬取url对应页面
	result, err := HttpGet(url)
	if err != nil {
		fmt.Println("httpget err", err)
		return
	}
	//fmt.Println("result=", result)
	// 解析，编译正则表达式  ---电影名称
	ret := regexp.MustCompile(`<img width="100" alt="(?s:(.*?))"`)
	filmName := ret.FindAllStringSubmatch(result, -1)
	for _, name := range filmName {
		fmt.Println("name", name[1])
	}

	ret2 := regexp.MustCompile(`<span class="rating_num" property="v:average">(?s:(.*?))<`)
	filmScore := ret2.FindAllStringSubmatch(result, -1)
	for _, score := range filmScore {
		fmt.Println("score", score[1])
	}

	savToFile(index, filmName, filmScore)

}

// 爬取指定url页面，返回result
func HttpGet(url string) (result string, err error) {
	req, _ := http.NewRequest("GET", url, nil)
	// 设置头部信息
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36 OPR/66.0.3515.115")
	resp, err1 := (&http.Client{}).Do(req)
	//resp, err1 := http.Get(url)  //此方法已经被豆瓣视为爬虫，返回状态吗为418，所以必须伪装头部用上述办法
	if err1 != nil {
		err = err1
		return
	}
	defer resp.Body.Close()

	buf := make([]byte, 4096)

	//循环爬取整页数据
	for {
		n, err2 := resp.Body.Read(buf)
		if n == 0 {
			break
		}
		if err2 != nil && err2 != io.EOF {
			err = err2
			return
		}
		result += string(buf[:n])
	}

	return

}