from selenium import webdriver
from selenium.webdriver.common.keys import Keys
pkt = "https://www.packtpub.com/packt/offers/free-learning"
chromedriver = webdriver.Chrome()
chromedriver.get(pkt)
elem = chromedriver.find_element_by_class_name("twelve-days-claim")
elem.click()
elem2 = chromedriver.find_element_by_class_name("login-popup")
elem2.click()

1. username = chromedriver.find_element_by_id("login-form-email")
   2.username = chromedriver.find_element_by_id("email")
   3.username = chromedriver.find_element_by_id("email-wrapper")
   4.username = chromedriver.find_element_by_class_name("cf")