selenium--等待的三种方式

from selenium import webdriver
from time import sleep
driver = webdriver.Chrome()
driver.get('http://www.baidu.com')
sleep(2)
driver.find_element_by_css_selector('#kw').send_keys('python')
sleep(2)
driver.quit()

from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException
from time import sleep, ctime
driver = webdriver.Chrome()
driver.get('http://www.baidu.com')
sleep(2)
# 设置隐式等待，最多等待 5s，如果五秒内什么时候加载完就什么时候进行操作
driver.implicitly_wait(5)
try:
    print(ctime())
    driver.find_element_by_css_selector('#kw').send_keys('python')
    driver.find_element_by_css_selector('#su').click()
except NoSuchElementException  as msg:
    print(msg)
finally:
    print(ctime())
sleep(2)
driver.quit()

from selenium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.by import By
from time import sleep
driver = webdriver.Chrome()
driver.get('http://www.baidu.com')
sleep(2)
driver.find_element_by_css_selector('#kw').send_keys('python')
# 一共等待 5 秒钟，每 0.5s 找一次，直到通过 ID 找到
element = WebDriverWait(driver, 5, 0.5).until(EC.presence_of_element_located((By.ID, 'su')))
element.click()
sleep(2)
driver.quit()