nodejs ---- 起步

叁歲伎倆 2022-05-14 17:28 250阅读 0赞

跟着慕课敲了一波使用nodejs爬取慕课网

废话不多说，直接上代码，太晚了。安装的教程以及这篇的注释明天补上  
爬取这个页面：[https://www.imooc.com/learn/348][https_www.imooc.com_learn_348]  
创建一个：crawler.js

var http = require("https")
    var cheerio = require("cheerio")
    var url = "https://www.imooc.com/learn/348"
    
    function filterChapters(html){
        var $ = cheerio.load(html)
        var chapters = $(".chapter")
    
        var courseData = []
    
        chapters.each(function (item) {
            var chapter = $(this)
            var chapterTitle = chapter.find("h3").text()
            var videos = chapter.find(".video").children("li")
            var chapterData = {
                chapterTitle : chapterTitle,
                videos : []
            }
            videos.each(function (item) {
                var video = $(this).find(".J-media-item")
                var videoTitle = video.text()
                var id = video.attr("href").split("video/")[1]
                chapterData.videos.push({
                    title: videoTitle,
                    id: id
                })
            })
            courseData.push(chapterData)
        })
        return courseData
    }
    
    function printCourseInfo(courseData){
        courseData.forEach(function (item) {
            var chapterTitle = item.chapterTitle
            // console.log(chapterTitle + "\n")
            console.log(chapterTitle)
    
            item.videos.forEach(function (video) {
                // console.log(" 【" + video.id + "】 " + video.title +"\n")
                console.log("【" + video.id + "】" + video.title)
            })
        })
    }
    
    http.get(url, function (res) {
        var html = ""
        res.on("data", function (data) {
            html += data;
        })
    
        res.on("end", function () {
            var courseData = filterChapters(html)
            printCourseInfo(courseData)
        })
    }).on("error", function () {
        console.log("获取失败！")
    })

运行结果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NjM3NTU4_size_27_color_FFFFFF_t_70]

拜了个拜，晚安！

[https_www.imooc.com_learn_348]: https://www.imooc.com/learn/348
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NjM3NTU4_size_27_color_FFFFFF_t_70]: /images/20220503/4710bce2a23a4a298feeb8212499aa96.png