title: KeyError in python saying KeyError : 'value'
body: <p>I am trying to get the hidden elements in twitter login page. I followed a procedure which simply gets the hidden elements in that page. But the problem is when i try to get value of those elements, i am getting key error. the code is:</p>
  
  <pre><code>    import requests, lxml.html
  from bs4 import BeautifulSoup
  s = requests.session()
  login = s.get('https://twitter.com/login')
  login_html = lxml.html.fromstring(login.text)
  hidden_inputs = login_html.xpath(r'//form//input[@type="hidden"]')
  form = {x.attrib["name"]: x.attrib["value"] for x in hidden_inputs}
  print(form)
  </code></pre>
  
  <p>I am getting error at x.attrib['value']. How to rectify this?</p>