javascript download file

function download(filename, text) {
  var element = document.createElement('a');
  element.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(text));
  element.setAttribute('download', filename);

  element.style.display = 'none';
  document.body.appendChild(element);

  element.click();

  document.body.removeChild(element);
}

// Start file download.
download("hello.txt","This is the content of my file :)");
browser.downloads.download({url: "https://example.org/image.png"})$('a#someID').attr({target: '_blank', 
                    href  : 'http://localhost/directory/file.pdf'});<iframe id="download_iframe" style="display:none;"></iframe>
<script>
	document.getElementById('download_iframe').src = "/example/example.txt";
</script>

import urllib.request

print('Beginning file download with urllib2...')

url = 'http://i3.ytimg.com/vi/J---aiyznGQ/mqdefault.jpg'
urllib.request.urlretrieve(url, '/Users/scott/Downloads/cat.jpg')
function download(link) {
  var element = document.createElement('a');
  element.setAttribute('href', link);

  element.style.display = 'none';
  document.body.appendChild(element);

  element.click();

  document.body.removeChild(element);
}