导语
记得很久以前写过一些中国大学MOOC上的视频下载器,不过好像都已经年久失修了。正好最近有需要,所以重新写了一个,顺便上来分享一波,寒假大家也可以用它来下载点课程内卷一下:
废话不多说,让我们愉快地开始吧~
开发工具
Python版本:3.7.8
相关模块:
DecryptLogin模块;
tqdm模块;
click模块;
argparse模块;
以及一些python自带的模块。
环境搭建
安装Python并添加到环境变量,pip安装需要的相关模块即可。
先睹为快
运行方式:
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python moocdl.py - - url 课程链接 |
效果如下:
随便挑的一个课程测试的,结果是m3u8格式的,所以下载起来有点慢。默认会把所有的课件这些东西也一起下载下来放到对应的目录。
原理简介
首先,我们需要先模拟登录中国大学MOOC,这样才能下载对应的课程资料,这里借助公众号之前开源的DecryptLogin包就好啦:
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'''登录''' def login( self , username, password): lg = login.Login() infos_return, session = lg.icourse163(username, password) return infos_return, session |
接着,我们简单讲解一下如何下载对应课程里的资料。首先,我们需要获得课程相关的基本资料,随便点开个课程主页就可以发现直接在返回的页面里就有:
提取我们需要的课程信息的代码实现如下:
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# 从课程主页面获取信息 url = url.replace( 'learn/' , 'course/' ) response = self .session.get(url) term_id = re.findall(r 'termId : "(\d+)"' , response.text)[ 0 ] course_name = ' - ' .join(re.findall(r 'name:"(.+)"' , response.text)) course_name = self .filterBadCharacter(course_name) course_id = re.findall(r 'https?://www.icourse163.org/(course|learn)/\w+-(\d+)' , url)[ 0 ] print (f '从课程主页面获取的信息如下:\n\t[课程名]: {course_name}, [课程ID]: {course_name}, [TID]: {term_id}' ) |
接着利用这些信息来爬取对应的资源列表:
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# 获取资源列表 resource_list = [] data = { 'tid' : term_id, 'mob-token' : self .infos_return[ 'results' ][ 'mob-token' ], } response = self .session.post( 'https://www.icourse163.org/mob/course/courseLearn/v1' , data = data) course_info = response.json() file_types = [ 1 , 3 , 4 ] for chapter_num, chapter in enumerate (course_info.get( 'results' , {}).get( 'termDto' , {}).get( 'chapters' , [])): for lesson_num, lesson in enumerate (chapter.get( 'lessons' , [])) if chapter.get( 'lessons' ) is not None else []: for unit_num, unit in enumerate (lesson.get( 'units' , [])): if unit[ 'contentType' ] not in file_types: continue savedir = course_name self .checkdir(savedir) for item in [ self .filterBadCharacter(chapter[ 'name' ]), self .filterBadCharacter(lesson[ 'name' ]), self .filterBadCharacter(unit[ 'name' ])]: savedir = os.path.join(savedir, item) self .checkdir(savedir) if unit[ 'contentType' ] = = file_types[ 0 ]: savename = self .filterBadCharacter(unit[ 'name' ]) + '.mp4' resource_list.append({ 'savedir' : savedir, 'savename' : savename, 'type' : 'video' , 'contentId' : unit[ 'contentId' ], 'id' : unit[ 'id' ], }) elif unit[ 'contentType' ] = = file_types[ 1 ]: savename = self .filterBadCharacter(unit[ 'name' ]) + '.pdf' resource_list.append({ 'savedir' : savedir, 'savename' : savename, 'type' : 'pdf' , 'contentId' : unit[ 'contentId' ], 'id' : unit[ 'id' ], }) elif unit[ 'contentType' ] = = file_types[ 2 ]: if unit.get( 'jsonContent' ): json_content = eval (unit[ 'jsonContent' ]) savename = self .filterBadCharacter(json_content[ 'fileName' ]) resource_list.append({ 'savedir' : savedir, 'savename' : savename, 'type' : 'rich_text' , 'jsonContent' : json_content, }) print (f '成功获得资源列表, 数量为{len(resource_list)}' ) |
最后根据资源类型解析下载即可:
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# 下载对应资源 pbar = tqdm(resource_list) for resource in pbar: pbar.set_description(f 'downloading {resource["savename"]}' ) # --下载视频 if resource[ 'type' ] = = 'video' : data = { 'bizType' : '1' , 'mob-token' : self .infos_return[ 'results' ][ 'mob-token' ], 'bizId' : resource[ 'id' ], 'contentType' : '1' , } while True : response = self .session.post( 'https://www.icourse163.org/mob/j/v1/mobileResourceRpcBean.getResourceToken.rpc' , data = data) if response.json()[ 'results' ] is not None : break time.sleep( 0.5 + random.random()) signature = response.json()[ 'results' ][ 'videoSignDto' ][ 'signature' ] data = { 'enVersion' : '1' , 'clientType' : '2' , 'mob-token' : self .infos_return[ 'results' ][ 'mob-token' ], 'signature' : signature, 'videoId' : resource[ 'contentId' ], } response = self .session.post( 'https://vod.study.163.com/mob/api/v1/vod/videoByNative' , data = data) # ----下载视频 videos = response.json()[ 'results' ][ 'videoInfo' ][ 'videos' ] resolutions, video_url = [ 3 , 2 , 1 ], None for resolution in resolutions: for video in videos: if video[ 'quality' ] = = resolution: video_url = video[ "videoUrl" ] break if video_url is not None : break if '.m3u8' in video_url: self .m3u8download({ 'download_url' : video_url, 'savedir' : resource[ 'savedir' ], 'savename' : resource[ 'savename' ], }) else : self .defaultdownload({ 'download_url' : video_url, 'savedir' : resource[ 'savedir' ], 'savename' : resource[ 'savename' ], }) # ----下载字幕 srt_info = response.json()[ 'results' ][ 'videoInfo' ][ 'srtCaptions' ] if srt_info: for srt_item in srt_info: srt_name = os.path.splitext(resource[ 'savename' ])[ 0 ] + '_' + srt_item[ 'languageCode' ] + '.srt' srt_url = srt_item[ 'url' ] response = self .session.get(srt_url) fp = open (os.path.join(resource[ 'savedir' ], srt_name), 'wb' ) fp.write(response.content) fp.close() # --下载PDF elif resource[ 'type' ] = = 'pdf' : data = { 't' : '3' , 'cid' : resource[ 'contentId' ], 'unitId' : resource[ 'id' ], 'mob-token' : self .infos_return[ 'results' ][ 'mob-token' ], } response = self .session.post( 'http://www.icourse163.org/mob/course/learn/v1' , data = data) pdf_url = response.json()[ 'results' ][ 'learnInfo' ][ 'textOrigUrl' ] self .defaultdownload({ 'download_url' : pdf_url, 'savedir' : resource[ 'savedir' ], 'savename' : resource[ 'savename' ], }) # --下载富文本 elif resource[ 'type' ] = = 'rich_text' : download_url = 'http://www.icourse163.org/mob/course/attachment.htm?' + urlencode(resource[ 'jsonContent' ]) self .defaultdownload({ 'download_url' : download_url, 'savedir' : resource[ 'savedir' ], 'savename' : resource[ 'savename' ], }) |
ok,大功告成啦,写的有点简略,因为晚上还有点其他事。大家可以自己在手机端抓包试试,很简单的~
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原文链接:https://zhuanlan.zhihu.com/p/465060428