NodeJSのaxiosモジュールは爬虫類機能を実現します.

const fs = require("fs");
const axios = require("axios");
const cheerio = require("cheerio");

axios.get("https://movie.douban.com/chart").then(res=>{
    //console.log(res.data)
    //fs.writeFileSync("1.html", res.data);

    var $ = cheerio.load(res.data);  //       

    var data = [];
    var all = 0;
    var min;
    var minIndex;
    var max;
    var maxIndex;

    $(".pl2").each(function( ind, el){
        var elem = $(el);
        var title = elem.children("a").text().split("/")[0].replace(/
/g, '').replace(/\s/g, '');
        var score = Number(elem.find(".rating_nums").text());

        if( min === undefined ){
            min = score;
        }
        if( max === undefined ){
            max = score;
        }

        if( scoremax ){
            max = score;
            maxIndex = ind;
        }


        data.push({
            title,
            score
        })

        all+=Number(score); //    
    })

    var pjf = all / data.length;    //    
    console.log('  ：'+all.toString());
    console.log('   ：'+pjf.toString());
    console.log('   ：'+min+'          ：'+minIndex+'      '+data[minIndex].title);
    console.log('   ：'+max+'          ：'+maxIndex+'      '+data[maxIndex].title);

})