By

from selenium import webdriver
from selenium.webdriver.common.by import By

driver = webdriver.Firefox()
driver.get('https://www.baidu.com/')

driver.find_element_by_id('su')
driver.find_element(By.ID, 'kw').send_keys('抠脚')
By.ID
By.CLASS_NAME
By.LINK_TEXT
By.NAME
By.XPATH
By.CSS_SELECTOR