前言
现在知乎允许上传视频,奈何不能下载视频,好气哦,无奈之下研究一下了,然后撸了代码,方便下载视频保存。
接下来以 猫为什么一点也不怕蛇? 回答为例,分享一下整个下载过程。
相关学习推荐:python视频教程
调试一下
打开 f12, 找到光标,如下图:
然后将光标移动到视频上。如下图:
咦这是什么?视野中出现了一条神秘的链接: https://www.zhihu.com/video/xxxxx,让我们将这条链接复制到浏览器上,然后打开:
似乎这就是我们要找的视频,不要着急,让我们看一看,网页的请求,然后你会发现一个很有意思的请求(重点来了):
让我们自己看一下数据吧:
{	"playlist": {		"ld": {			"width": 360,			"format": "mp4",			"play_url": "https://vdn.vzuu.com/ld/05fc411e-d8e0-11e8-bb8b-0242ac112a0b.mp4?auth_key=1541477643-0-0-987c2c504d14ab1165ce2ed47759d927&expiration=1541477643&disable_local_cache=1",			"duration": 17,			"size": 1123111,			"bitrate": 509,			"height": 640		},		"hd": {			"width": 720,			"format": "mp4",			"play_url": "https://vdn.vzuu.com/hd/05fc411e-d8e0-11e8-bb8b-0242ac112a0b.mp4?auth_key=1541477643-0-0-8b8024a22a62f097ca31b8b06b7233a1&expiration=1541477643&disable_local_cache=1",			"duration": 17,			"size": 4354364,			"bitrate": 1974,			"height": 1280		},		"sd": {			"width": 480,			"format": "mp4",			"play_url": "https://vdn.vzuu.com/sd/05fc411e-d8e0-11e8-bb8b-0242ac112a0b.mp4?auth_key=1541477643-0-0-5948c2562d817218c9a9fc41abad1df8&expiration=1541477643&disable_local_cache=1",			"duration": 17,			"size": 1920976,			"bitrate": 871,			"height": 848		}	},	"title": "",	"duration": 17,	"cover_info": {		"width": 720,		"thumbnail": "https://pic2.zhimg.com/80/v2-97b9435a0c32d01c7c931bd00120327d_b.jpg",		"height": 1280	},	"type": "video",	"id": "1039146361396174848",	"misc_info": {}}
没错了,我们要下载的视频就在这里面,其中 ld 代表普清,sd 代表标清, hd 代表高清,把相应链接再次在浏览器打开,然后右键保存就可以下载视频了。
代码
知道整个流程是什么样子,接下来撸代码的过程就简单了,这里就不过再做过多解释了,直接上代码:
# -*- encoding: utf-8 -*-import reimport requestsimport uuidimport datetimeclass downloadvideo:  __slots__ = [    'url', 'video_name', 'url_format', 'download_url', 'video_number',    'video_api', 'clarity_list', 'clarity'  ]  def __init__(self, url, clarity='ld', video_name=none):    self.url = url    self.video_name = video_name    self.url_format = "https://www.zhihu.com/question/\d+/answer/\d+"    self.clarity = clarity    self.clarity_list = ['ld', 'sd', 'hd']    self.video_api = 'https://lens.zhihu.com/api/videos'  def check_url_format(self):    pattern = re.compile(self.url_format)    matches = re.match(pattern, self.url)    if matches is none:      raise valueerror(        "链接格式应符合:https://www.zhihu.com/question/{number}/answer/{number}"      )    return true  def get_video_number(self):    try:      headers = {        'user-agent':        'mozilla/5.0 (macintosh; intel mac os x 10_12_6) applewebkit/537.36 (khtml, like gecko) chrome/66.0.3359.181 safari/537.36'      }      response = requests.get(self.url, headers=headers)      response.encoding = 'utf-8'      html = response.text      video_ids = re.findall(r'data-lens-id="(\d+)"', html)      if video_ids:        video_id_list = list(set([video_id for video_id in video_ids]))        self.video_number = video_id_list[0]        return self      raise valueerror("获取视频编号异常:{}".format(self.url))    except exception as e:      raise exception(e)  def get_video_url_by_number(self):    url = "{}/{}".format(self.video_api, self.video_number)    headers = {}    headers['referer'] = 'https://v.vzuu.com/video/{}'.format(      self.video_number)    headers['origin'] = 'https://v.vzuu.com'    headers[      'user-agent'] = 'mozilla/5.0 (windows nt 10.0; wow64) applewebkit/537.36 (khtml, like gecko) chrome/70.0.3538.67 safari/537.36'    headers['content-type'] = 'application/json'    try:      response = requests.get(url, headers=headers)      response_dict = response.json()      if self.clarity in response_dict['playlist']:        self.download_url = response_dict['playlist'][          self.clarity]['play_url']      else:        for clarity in self.clarity_list:          if clarity in response_dict['playlist']:            self.download_url = response_dict['playlist'][              self.clarity]['play_url']            break      return self    except exception as e:      raise exception(e)  def get_video_by_video_url(self):    response = requests.get(self.download_url)    datetime_str = datetime.datetime.now().strftime("%y-%m-%d %h-%m-%s")    if self.video_name is not none:      video_name = "{}-{}.mp4".format(self.video_name, datetime_str)    else:      video_name = "{}-{}.mp4".format(str(uuid.uuid1()), datetime_str)    path = "{}".format(video_name)    with open(path, 'wb') as f:      f.write(response.content)  def download_video(self):    if self.clarity not in self.clarity_list:      raise valueerror("清晰度参数异常,仅支持:ld(普清),sd(标清),hd(高清)")    if self.check_url_format():      return self.get_video_number().get_video_url_by_number().get_video_by_video_url()if __name__ == '__main__':  a = downloadvideo('https://www.zhihu.com/question/53031925/answer/524158069')  print(a.download_video())
结语
代码还有优化空间,这里面我只是下载了回答中的第一个视频,理论上应该存在一个回答下可以有多个视频的。如果还有什么疑问或者建议,可以多多交流。
相关学习推荐:python视频教程
以上就是学习python 抓取知乎指定回答下视频的方法的详细内容。
   
 
   