title: How to download a video directly from a url using python?
body: <p>I am new to python and I want to download a video from a given URL. So 
  far I've heard about <code>urllib</code>, <code>urllib2</code> and <code>requests</code> modules that help to download a video from URL, but when I tried them I apparently got all the data on that
  page and I don't know what I got, or even if the video is in there since the size of the output file is usually 50-170 KB and videos are usually way more than that. I'll post two codes of mine that are meant to download a video so you can tell me if they have any problem. If they are okay, can you tell me how to separate the video from what I got or if the video is even there?</p>
  
  <p>1.</p>
  
  <pre><code>import requests
  
  def download_file(url):
   local_filename = url.split('/')[-1]
  
   r = requests.get(url, stream=True)
   with open("D://"+local_filename, 'wb') as f:
      for chunk in r.iter_content(chunk_size=1024):
          if chunk: 
              f.write(chunk)
  
  earl = "https://www.youtube.com/watch?v=DBYjZTdrJlA"
  download_file(earl)
  </code></pre>
  
  <p>2.</p>
  
  <pre><code> import urllib2
   import os
  
  
   earl="https://www.youtube.com/watch?v=DBYjZTdrJlA"
   y= True
   try: response=urllib2.urlopen(earl)
   except urllib2.HTTPError:
    print "oopsy, website wont allow it"
    y=False
  
  
   def downloader(url):
     response=urllib2.urlopen(url)
     info = response.read()
     print info
     fx= open(os.path.join("D://", "video.mp4"),'wb')
     for line in info:
       fx.write(line)
     fx.close()
     print "done"
  
    if(y):
    downloader(earl)     
  </code></pre>