selenium 页面等待

需要等待的原因

如果网页使用了Ajax异步请求, 当浏览器加载页面时, 各种元素的加载时间不同, 定位元素可能会因为响应时间问题出现定位不到的异常: ElementNotVisibleException .
使用 waits , 解决元素等待加载的问题.

显式等待

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

driver = webdriver.Firefox()
driver.get("http://www.baidu.com")
try:
    element = WebDriverWait(driver, 10).until(
        EC.presence_of_element_located((By.ID, "kw"))
    )
finally:
    driver.quit()

from selenium.webdriver.support import expected_conditions as EC

wait = WebDriverWait(driver, 10)
element = wait.until(EC.element_to_be_clickable((By.ID,'kw')))

隐式等待

from selenium import webdriver

driver = webdriver.Firefox()
driver.implicitly_wait(10) # seconds
driver.get("https://www.baidu.com")
myDynamicElement = driver.find_element_by_id("myDynamicElement")