title: Python, Selenium, download all MIME types
body: <p>I am trying to download some files using selenium webdriver for Firefox.
  How to set option <code>browser.helperApps.neverAsk</code> for any MIME type?</p>
  
  <p>Now this option working only for <code>application/pdf</code> (in my script):</p>
  
  <pre><code>#selenium profile
  profile = webdriver.FirefoxProfile()
  profile.set_preference('browser.download.dir', download_dir)
  profile.set_preference('browser.download.folderList', 2)
  profile.set_preference('browser.download.manager.showWhenStarting', False)
  profile.set_preference('browser.helperApps.neverAsk.saveToDisk', 'application/pdf')
  #-------------------
  driver = webdriver.Firefox(firefox_profile=profile)
  </code></pre>