1、显式等待
from selenium.webdriver.support import expected_conditions as EC from selenium.webdriver.support.wait import WebDriverWait def text_by_xpath(self,loc): '''依据元素返回text信息''' # / self.logger.debug(loc) for i in range(5): try: WebDriverWait(self.driver,3,1).until( EC.presence_of_element_located(loc) ) text = self.find_element(*loc).text if text!=None: return text except Exception as e: # self.logger.debug(e) pass else: # self.logger.debug("无内容返回") pass
在设置时间内,每隔一段时间对页面进行检测
expected_conditions提供的判断方法:
除了使用该类,还可使用 is_displayed()方法进行判断元素是否可见
from selenium import webdriver from time import sleep ,ctime driver = webdriver.Firefox() driver.get("http://www.baidu.com") print(ctime()) for i in range(10): try: el = driver.find_element_by_id("kw1") if el.is_displayed(): break except:pass sleep(1) else: print("time out") driver.close() print(ctime())
2、隐式等待
通过一定时长等待页面上某元素加载完成。如果超出设置的时长还没有被加载,则抛出异常
from selenium import webdriver from time import sleep ,ctime from selenium.common.exceptions import NoSuchElementException driver = webdriver.Firefox() driver.implicitly_wait(10) driver.get("http://www.baidu.com") try: print(ctime()) el = driver.find_element_by_id("kw1").send_keys("111") except NoSuchElementException as e: print(e) finally: driver.close() print(ctime())
3、sleep休眠方式
from selenium import webdriver
from time import sleep ,ctime
from selenium.common.exceptions import NoSuchAttributeException
driver = webdriver.Firefox()
driver.implicitly_wait(10)
driver.get("http://www.baidu.com")
try:
print(ctime())
el = driver.find_element_by_id("kw1").send_keys("111")
except NoSuchAttributeException as e
print(e)
finally:
driver.close()
print(ctime())