Sel4：显示等待

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
from time import sleep

driver=webdriver.Chrome()
driver.get("http://www.baidu.com")

driver.find_element_by_css_selector("#kw").send_keys("python")
sleep(2)

#driver=WebDriver的意思    5表示超时间     0.5表示每0.5秒检测一次    

#until(EC.presence_of_element_located((By.ID,"su")))  表示直到找到元素 su 为止，使用By.ID的方法来找

element=WebDriverWait(driver,5,0.5).until(EC.presence_of_element_located((By.ID,"su"))) 
element.click() 
sleep(2) 
driver.quit()