from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
driver = webdriver.Firefox()
url = 'http://www.cfnews.net/user/login'
driver.get(url)
wait = WebDriverWait(driver, 10)
login_form = wait.until(EC.visibility_of_element_located((By.CSS_SELECTOR,
    'input#nom-user')))
login_form.send_keys('a')
Селен — ElementNotVisibleException