当尝试从亚马逊网络抓取图像时收到错误。目的是下载书籍封面。
(node:26904) UnhandledPromiseRejectionWarning: Error: undefined is not a valid uri or options object.
at request (C:\Users\Isaac\Desktop\webscrape_with_cheerio\node_modules\request\index.js:44:11)
at PromisseHandle._RejectOrResolve (C:\Users\Isaac\Desktop\webscrape_with_cheerio\node_modules\node-image-downloader\src\image-downloader.js:86:5)
at new Promise (<anonymous>)
at ImageDownloader (C:\Users\Isaac\Desktop\webscrape_with_cheerio\node_modules\node-image-downloader\src\image-downloader.js:98:26)
at Request._callback (C:\Users\Isaac\Desktop\webscrape_with_cheerio\index.js:22:13)
at Request.self.callback (C:\Users\Isaac\Desktop\webscrape_with_cheerio\node_modules\request\request.js:185:22)
at Request.emit (events.js:210:5)
at Request.<anonymous> (C:\Users\Isaac\Desktop\webscrape_with_cheerio\node_modules\request\request.js:1154:10)
at Request.emit (events.js:210:5)
at IncomingMessage.<anonymous> (C:\Users\Isaac\Desktop\webscrape_with_cheerio\node_modules\request\request.js:1076:12)
(node:26904) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)
(node:26904) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with
a non-zero exit code.
到目前为止,这是我的代码。我相信我的错误源于这一行;
var imagesrc = $(“。a行中心对齐点击式img”)。attr('src')
我可能需要通过书籍网址访问Class,尽管我可能错了。
const express = require('express');
const cheerio = require('cheerio');
const download = require('node-image-downloader');
const request = require('request');
const app = express();
app.get('/', (req, res) => {
var url = "https://www.amazon.com/Black-Swan-Improbable-Robustness-Fragility/dp/081297381X"
// makeing a request
request(url,(error, response,html) => {
if (!error){
//console.log(html);
var $ = cheerio.load(html)
var imagesrc = $(".a-row center-align litb-on-click img").attr('src')
//download the image
download({
imgs: [
{
uri:imagesrc
}
],
dest:'./downloads'
})
.then((info) => {
console.log("Download Complete")
process.exit(1)
})
}
})
})
app.listen(5000)
答案 0 :(得分:0)
这里行点击中心对齐的litb是类
要选择一个类,我们需要使用class-selector。 (点)
请尝试如下更新您的imagesrc变量
var imagesrc = $(".a-row.center-align.litb-on-click img").attr('src');
空格不是强制性的。