智能休眠时间的使用
from selenium.webdriver.support.wait import WebDriverWait引入智能休眠时间
wait=WebDriverWait(driver,30)
wait.until(lambda the _driver:the_driver.find_element_by_id('dropdownl').is_displayed(0)
用以上两行或者直接合并成一行
webDriverWait(driver,10).until(lanbda the driver:the_driver.find_element_by_id('dropdownl').is_dispayed())