JS Python URL 和网页内容 爬虫如何获取 生成的 python爬取js动态网页

还记得在之前一篇python开发电影查询系统（一）—python实现后台数据中，对电影的下载地址无法进行爬取，原因是下载地址在网页源码中无法查看，而是存放在js中，动态加载了。所以在爬取时，我在文章中写道

现在，我们找到了攻破他反爬的方法。下面我来详细介绍一下。

robobrowser库所做的事情就是模拟你真实的浏览器，并可加载动态js页面，从而爬取数据。是不是很牛逼啊。

一、robobrowser库的下载安装。

直接用python的pip安装即可

pip3 install robobrowser

二、使用方法

安装完成后，使用help查看使用方法。

• 我们在电影首页，随便点一个电影链接进入到电影详情页面。比如http://www.bd-film.co/gq/25601.htm；
• 进入以后，我们打开F12，查看网页源代码。刷新页面，查看network
  
  将General和Request headers复制下来。

# -*- coding: utf-8 -*-
import robobrowser
import time
from requests import Session
    urls = []
    ua = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36'
    session = Session()
    # 直接从浏览器的F12取的headers，不这样的话，网站有反爬虫机制
    # 数据爬了几十条后就返回无数据内容的页面了
    session.headers = {
    "Request URL": film_url,
    "Request Method": "GET",
    #"Remote Address": "",
    "Referrer Policy": "no-referrer-when-downgrade",
    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8",
    "Accept-Encoding": "gzip, deflate",
    "Accept-Language": "zh-CN,zh;q=0.9",
    "Cache-Control": "max-age=0",
    "Cookie": "Hm_lvt_0fae9a0ed120850d7a658c2cb0783b55=1527565708,1527653577,1527679892,1527729123; Hm_lvt_cdce8cda34e84469b1c8015204129522=1527565709,1527653577,1527679892,1527729124; _site_id_cookie=1; clientlanguage=zh_CN; JSESSIONID=5AA866B8CDCDC49CA4B13D041E02D5E1; yunsuo_session_verify=c1b9cd7af99e39bbeaf2a6e4127803f1; Hm_lpvt_0fae9a0ed120850d7a658c2cb0783b55=1527731668; Hm_lpvt_cdce8cda34e84469b1c8015204129522=1527731668",
    "Host": "www.bd-film.co",
    "Proxy-Connection": "keep-alive",
    "Upgrade-Insecure-Requests": "1",
    "User-Agent": ua
    }

• 查看每个下载url的源码，借助css选择器，把url的selecter地址复制下来。

我们多复制几个看看

#downlist > div > div > div:nth-child(1) > div
#downlist > div > div > div:nth-child(2) > div
#downlist > div > div > div:nth-child(3) > div

发现规律，所有下载地址的selecter地址中都有downlist ，所以我们会有下面代码中处理机制。

rb = robobrowser.RoboBrowser(parser="html.parser", session=session)
rb.open(url=film_url)
r = rb.select('#downlist')
if not r:
    # print(rb.response.content.decode())
    raise RuntimeError("获取网页内容失败")

• 根据“复制地址”所对应的url（已找到规律），来获取其后面的迅雷、小米等具体的下载链接。
  现在我们来看看他们具体对应到迅雷，小米，百度云盘的下载链接。

代码如下：

r = r[0]
for v in range(128):#这里循环次数根据你想爬取的数目为准
    id_name = '#real_address_%d' % v
    dl = r.select(id_name)
    if not dl:
        break
    dl = dl[0].select('.form-control')[0].text
    #这里dl就是具体下载地址了

OK，完整代码如下：

# -*- coding: utf-8 -*-
import robobrowser
import time

def get_bd_film_download_urls(film_url):
    from requests import Session
    urls = []
    try:
        ua = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36'
        session = Session()
        # 直接从浏览器的F12取的headers，不这样的话，网站有反爬虫机制
        # 数据爬了几十条后就返回无数据内容的页面了
        session.headers = {
        "Request URL": film_url,
        "Request Method": "GET",
        #"Remote Address": "",
        "Referrer Policy": "no-referrer-when-downgrade",
        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8",
        "Accept-Encoding": "gzip, deflate",
        "Accept-Language": "zh-CN,zh;q=0.9",
        "Cache-Control": "max-age=0",
        "Cookie": "Hm_lvt_0fae9a0ed120850d7a658c2cb0783b55=1527565708,1527653577,1527679892,1527729123; Hm_lvt_cdce8cda34e84469b1c8015204129522=1527565709,1527653577,1527679892,1527729124; _site_id_cookie=1; clientlanguage=zh_CN; JSESSIONID=5AA866B8CDCDC49CA4B13D041E02D5E1; yunsuo_session_verify=c1b9cd7af99e39bbeaf2a6e4127803f1; Hm_lpvt_0fae9a0ed120850d7a658c2cb0783b55=1527731668; Hm_lpvt_cdce8cda34e84469b1c8015204129522=1527731668",
        "Host": "www.bd-film.co",
        "Proxy-Connection": "keep-alive",
        "Upgrade-Insecure-Requests": "1",
        "User-Agent": ua
        }
        rb = robobrowser.RoboBrowser(parser="html.parser", session=session)
        rb.open(url=film_url)
        if rb.response.status_code != 200:
            return  urls
        r = rb.select('#downlist')#使用css过滤器筛选出下载链接的关键字段
        if not r:
            # print(rb.response.content.decode())
            raise RuntimeError("获取网页内容失败")

        r = r[0]
        for v in range(128):
            id_name = '#real_address_%d' % v
            dl = r.select(id_name)
            if not dl:
                break
            dl = dl[0].select('.form-control')[0].text
            urls.append(dl)
    except Exception as err:
        print('error:',film_url, err)
    return urls
if __name__ == '__main__':

    for i in range(25000, 25700):
        ul = 'http://www.bd-film.co/zx/%d.htm' % i
        down_urls = get_bd_film_download_urls(ul)
        if down_urls:
            s = '-->'
            print(ul, s, ','.join(down_urls))
        time.sleep(1)
        # break

效果展示：

将–>后面的地址复制迅雷，就可以下载了~~快去试试吧！