Selenium驱动无法定位并操作QBCC网站输入框问题求助

问题背景 #

正在编写爬虫抓取QBCC网站（https://my.qbcc.qld.gov.au/myQBCC/s/findlocalcontractor），已成功处理页面两个下拉菜单，但无法定位并操作目标输入框。该输入框HTML标签如下：

<input lwc-enmikoh2qu="" class="slds-input" aria-errormessage="help-message-54" id="input-54" name="find" part="input" placeholder="Type suburb, post code here..." type="text">

已尝试的失败方法 #

• 通过ID定位，但ID会频繁变化，提示元素未找到
• 通过类名、name属性、CSS选择器、XPATH、标签名定位，均提示元素未找到
• 使用JavaScript获取元素，返回None，无法点击或输入内容
• 使用隐式等待和显式等待等待元素加载，仍提示元素未找到

最后尝试的代码片段 #

location = WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CSS_SELECTOR, 'input[class*="slds-input"]')))
#location = driver.execute_script('return document.querySelector(\'input[placeholder="Type suburb, post code here..."]\');')
location.click()
location.send_keys('New Auckland')
location.send_keys(Keys.ENTER)

完整参考代码 #

from bs4 import BeautifulSoup
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support.ui import Select
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
import time

URL = "https://my.qbcc.qld.gov.au/myQBCC/s/findlocalcontractor"

driver = webdriver.Chrome()
driver.get(URL)

time.sleep(8)

industry = Select(driver.find_element(By.ID, '28:2;a'))
industry.select_by_index(4)

range = Select(driver.find_element(By.ID, '46:2;a'))
range.select_by_index(3)

time.sleep(1)

location = WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CSS_SELECTOR, 'input[class*="slds-input"]')))
#location = driver.execute_script('return document.querySelector(\'input[placeholder="Type suburb, post code here..."]\');')
location.click()
location.send_keys('New Auckland')
location.send_keys(Keys.ENTER)

time.sleep(3)

page_source = driver.page_source

driver.quit()

soup = BeautifulSoup(page_source, "html.parser")

解决方案 #

1. 检查并切换iframe #

该网站基于Salesforce LWC构建，大概率存在iframe嵌套。输入框可能在iframe内，需先切换到对应iframe再定位：

# 等待iframe加载并切换
iframe = WebDriverWait(driver, 15).until(EC.presence_of_element_located((By.TAG_NAME, 'iframe')))
driver.switch_to.frame(iframe)

# 之后再定位输入框
location = WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CSS_SELECTOR, 'input[placeholder="Type suburb, post code here..."]')))

2. 使用多属性组合定位 #

结合多个稳定属性编写定位器，提升准确性：

• CSS选择器：input.slds-input[name="find"][placeholder="Type suburb, post code here..."]
• XPATH：//input[@class="slds-input" and @name="find" and @placeholder="Type suburb, post code here..."]

代码示例：

location = WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CSS_SELECTOR, 'input.slds-input[name="find"][placeholder="Type suburb, post code here..."]')))
location.click()
location.send_keys('New Auckland')
location.send_keys(Keys.ENTER)

3. 用JavaScript直接操作元素 #

如果元素存在但无法点击，直接通过JS设置值并触发事件：

location = WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.CSS_SELECTOR, 'input.slds-input[name="find"]')))
# 设置输入值
driver.execute_script("arguments[0].value = 'New Auckland';", location)
# 触发回车提交
driver.execute_script("arguments[0].dispatchEvent(new KeyboardEvent('keypress', {key: 'Enter'}));", location)

4. 替换固定sleep为显式等待 #

避免使用time.sleep()，改用显式等待确保下拉菜单操作完成后再处理输入框：

# 等待第一个下拉菜单加载并选择
industry_select = WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.ID, '28:2;a')))
industry = Select(industry_select)
industry.select_by_index(4)

# 等待第二个下拉菜单加载并选择
range_select = WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.ID, '46:2;a')))
range = Select(range_select)
range.select_by_index(3)

# 等待输入框可操作
location = WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.CSS_SELECTOR, 'input.slds-input[name="find"]')))

内容的提问来源于stack exchange，提问作者SolidOpt