import requests
from bs4 import BeautifulSoup

'''
URL of the archive web-page which provides link to
all video lectures. It would have been tiring to
download each video manually.
In this example, we first crawl the webpage to extract
all the links and then download videos.
'''

# specify the URL of the archive here
archive_url = "http://www-personal.umich.edu/~csev/books/py4inf/media/"


def get_video_links():
 # create response object
 r = requests.get(archive_url)

 # create beautiful-soup object
 soup = BeautifulSoup(r.content, 'html5lib')

 # find all links on web-page
 links = soup.findAll('a')

 # filter the link sending with .mp4
 video_links = [archive_url + link['href'] for link in links if link['href'].endswith('mp4')]

 return video_links


def download_video_series(video_links):
 for link in video_links:

 '''iterate through all links in video_links
 and download them one by one'''

 # obtain filename by splitting url and getting 
 # last string
 file_name = link.split('/')[-1]

 print("Downloading the file:%s" % file_name)

 # create response object
 r = requests.get(link, stream=True)

 # download started
 with open(file_name, 'wb') as f:
 for chunk in r.iter_content(chunk_size=1024 * 1024):
 if chunk:
 f.write(chunk)

 print("%s downloaded!\n" % file_name)

 print("All videos are downloaded!")
 return


if __name__ == "__main__":
 # getting all video links
 video_links = get_video_links()

 # download all videos
 download_video_series(video_links)