如何爬取B站视频？

1. 地址：www.bilibili.com/video/BV1WJ411e76...
2. 问题分析：通过拿到网页源代码，挨个试验网页源代码提供的地址，可以下载视频和音频，但是没有办法使用一个标准的方法去摘选正确的下载地址
3. 代码：

import requests

# 视频地址
# url = 'http://upos-sz-mirrorks3.bilivideo.com/upgcxcode/56/02/138550256/138550256-1-30080.m4s?e=ig8euxZM2rNcNbdlhoNvNC8BqJIzNbfqXBvEqxTEto8BTrNvN0GvT90W5JZMkX_YN0MvXg8gNEV4NC8xNEV4N03eN0B5tZlqNxTEto8BTrNvNeZVuJ10Kj_g2UB02J0mN0B5tZlqNCNEto8BTrNvNC7MTX502C8f2jmMQJ6mqF2fka1mqx6gqj0eN0B599M=&uipk=5&nbs=1&deadline=1604397291&gen=playurl&os=ks3bv&oi=3733189308&trid=ac6c918809ad47bb818af66c5c989895u&platform=pc&upsig=c4c5bc44e2df864e2c92e42e4b4a9668&uparams=e,uipk,nbs,deadline,gen,os,oi,trid,platform&mid=0&orderid=0,3&agrr=1&logo=80000000'

# 音频地址
# url = 'http://upos-sz-mirrorhw.bilivideo.com/upgcxcode/56/02/138550256/138550256-1-30232.m4s?e=ig8euxZM2rNcNbdlhoNvNC8BqJIzNbfqXBvEqxTEto8BTrNvN0GvT90W5JZMkX_YN0MvXg8gNEV4NC8xNEV4N03eN0B5tZlqNxTEto8BTrNvNeZVuJ10Kj_g2UB02J0mN0B5tZlqNCNEto8BTrNvNC7MTX502C8f2jmMQJ6mqF2fka1mqx6gqj0eN0B599M=&uipk=5&nbs=1&deadline=1604397291&gen=playurl&os=hwbv&oi=3733189308&trid=ac6c918809ad47bb818af66c5c989895u&platform=pc&upsig=03ee105c3f33a897ae38ccd9436df6fd&uparams=e,uipk,nbs,deadline,gen,os,oi,trid,platform&mid=0&orderid=0,3&agrr=1&logo=40000000'

headers = {
        'referer': 'https://www.bilibili.com/video/BV1WJ411e76L?from=search',
        'sec-ch-ua': '"\\Not;A\"Brand";v="99", "Google Chrome";v="85", "Chromium";v="85"',
        'sec-ch-ua-mobile': '?0',
        'sec-fetch-dest': 'empty',
        'sec-fetch-mode': 'cors',
        'sec-fetch-site': 'cross-site',
        'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.83 Safari/537.36'
        }

info = requests.get(url=url,headers=headers).content

print(info)

with open('1.mp4','wb') as f:
    f.write(info)

4. 网页源代码：从这个里面找的下载地址，挨个测试，吐了