python - 检查元素是否存在selenium python

Question

我正在接受 selenium python 培训，我可以做登录字段，并且需要在登录过程成功后检查特定元素。元素是这样定义的类名

if len(driver.find_element(By.CLASS_NAME, 'userIDSection').text)==30:
    print('Successful Login')
    break

如果登录成功我没有得到错误，但失败时我得到“没有这样的元素:无法定位元素”。如何正确检查元素以跳过此类错误？

** 尝试这段代码

WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CSS_SELECTOR, "input[name='login']"))).click()
time.sleep(3)
if len(driver.find_elements(By.CLASS_NAME, 'userIDSection'))>0:
    print('Successful Login')
    break
print('Login Failure')

我已经能够登录，但在这一行出现错误

TimeoutException                          Traceback (most recent call last)
<ipython-input-44-1f801f6ca398> in <module>
     28     WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "txtCaptcha"))).send_keys(captcha)
     29 
---> 30     WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CSS_SELECTOR, "input[name='login']"))).click()
     31     time.sleep(3)
     32     if len(driver.find_elements(By.CLASS_NAME, 'userIDSection'))>0:

C:\ProgramData\Anaconda3\lib\site-packages\selenium\webdriver\support\wait.py in until(self, method, message)
     78             if time.time() > end_time:
     79                 break
---> 80         raise TimeoutException(message, screen, stacktrace)
     81 
     82     def until_not(self, method, message=''):

TimeoutException: Message: 

检查元素时的代码应该打印“登录成功”并中断以 while True: 开头的循环

** 这是完整的代码，它可以工作并且登录正常，但我认为在断点之后出现错误

from selenium import webdriver 
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.by import By
from selenium.webdriver.support.wait import WebDriverWait
from selenium.common.exceptions import NoSuchElementException
import pytesseract
from PIL import Image
import time

def getCaptcha(img):
    pytesseract.pytesseract.tesseract_cmd=r'C:\\Program Files\\Tesseract-OCR\\tesseract.exe'
    img=Image.open(img)
    text=pytesseract.image_to_string(img, lang='eng',config='--psm 10 --oem 3 -c tessedit_char_whitelist=0123456789')
    return text

driver = webdriver.Chrome("C:/chromedriver")
driver.get("https://eservices.moj.gov.kw/")
WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CLASS_NAME, "headerTabLeft"))).click()

while True:
    WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "txtUserID"))).send_keys("username")
    WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "txtPWD"))).send_keys("password")
    
    imgName = 'Output.png'
    imgElement = WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.XPATH, "//*[@id='frmLogin']/table[1]/tbody/tr[1]/td/img")))
    imgElement.screenshot(imgName)
    time.sleep(5)
    captcha = getCaptcha(imgName)
    WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "txtCaptcha"))).send_keys(captcha)
    
    WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CSS_SELECTOR, "input[name='login']"))).click()
    time.sleep(3)
    
    try:
        element = driver.find_element(By.CLASS_NAME, 'userIDSection')
        break
    except:
    #except NoSuchElementException:
        print("No Element Found")
    
print('Successful Login')

Answer 1

使用.find_elements(注意复数)方法:

if len(driver.find_elements(By.CLASS_NAME, 'userIDSection'))>0:
    # DO YOUR THING

因此，如果不存在具有该类名的元素，您将得到 len = 0，但不会出错。