如何检查元素是否显示在网站上？

Question

我正在尝试创建一个登录测试，所以第一步是如果用户成功登录脚本应该在主页 post 登录中查找一个元素。

我的问题是，如果用户无法登录 python 会抛出 NoSuchElementException 异常并且不会转到其他地方。

from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException

def login_test(self):
    driver_location = 'D:\chromedriver.exe'
    os.environ["webdriver.chrome.driver"] = driver_location
    driver = webdriver.Chrome(driver_location)
    driver.maximize_window()
    driver.implicitly_wait(3)
    driver.get("http://www.example.com/")

prof_icon= driver.find_element_by_xpath("//button[contains(@class,'button')]")
if prof_icon.is_displayed():
    print("Success: logged in!")
else:
    print("Failure: Unable to login!")

我也试过：

 prof_icon= driver.find_element_by_xpath("//button[contains(@class,'button')]")
 try:   
      if prof_icon.is_displayed():
        print("Success: logged in!")
 except NoSuchElementException :
        print("Failure: Unable to login")

但是脚本总是崩溃并抛出异常。我只需要它在 else 中打印消息，以防元素未显示。

Answer 1

应该是：

except NoSuchElementException:  #correct name of exception
    print("Failure: Unable to login")

您可以查看元素是否存在，如果不存在则打印 "Failure: Unable to login"。注意 .find_elements_*.

中的复数 "s"

prof_icon = driver.find_elements_by_xpath("//button[contains(@class,'button')]")
if len(prof_icon) > 0
    print("Success: logged in!")
else:
    print("Failure: Unable to login")

希望对您有所帮助！

Answer 2

你很接近。要定位您必须为 visibility_of_element_located() 引入 WebDriverWait 的元素，您可以使用以下任一项 :

使用CSS_SELECTOR:

try:   
    WebDriverWait(driver, 20).until(EC.visibility_of_element_located((By.CSS_SELECTOR, "button.button")))
    print("Success: logged in!")
except TimeoutException:
    print("Failure: Unable to login")

使用XPATH:

try:   
    WebDriverWait(driver, 20).until(EC.visibility_of_element_located((By.XPATH, "//button[contains(@class,'button')]")))
    print("Success: logged in!")
except TimeoutException:
    print("Failure: Unable to login")

注意：您必须添加以下导入：

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import TimeoutException

如何检查元素是否显示在网站上？

How to check if element is displayed on website?

python

selenium

xpath

css-selectors

webdriverwait