import requests, lxml.html
import getpass
s = requests.session()

login = s.get('https://www.tianyancha.com/login')
login_html = lxml.html.fromstring(login.text)

hidden_inputs = login_html.xpath(r'//input[@class="loginState"]')
form = {x.attrib["value"] for x in hidden_inputs}
print form

username =input("Please insert your username:")
password = getpass.getpass("Please type in your password")
form['email'] = '{!r}'.format(username)
form['password'] = '{!r}'.format(password)
response = s.post('https://www.tianyancha.com/login', data=form)