How can I download just thumbnails using youtube-dl?
<p>I've been trying to download the thumbnails of a list of URL's (youtube videos) I have.</p>

<p>I've been using youtube-dl and I've worked it out to this so far:</p>

<pre><code>     import os

     with open('results.txt') as f:
          for line in f:
              os.system("youtube-dl " + "--write-thumbnail " + line)
</code></pre>

<p>Like this I'm able to download the thumbnails but I'm forced to downloading the youtube videos as well.</p>

<p>How can I just download the thumbnail?</p>