亲宝软件园·资讯

展开

Python公开课下载器

Charles的皮卡丘 人气:0

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:

python moocdl.py --url 课程链接

效果如下:

moocdl

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:

'''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:

# 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:

# 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:

# 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~

加载全部内容

相关教程
猜你喜欢
用户评论