如何用Python+Selenium点击表单内指定value的Input按钮？

我需要用Python和Selenium点击表单中value为CASTRO SALVADOR的input类型按钮，对应表单代码如下：

<form name="seleccionaEmpresaForm" action="setearContribuyente.do">
<table width="50%" align="center">
<tbody><tr><td height="5"></td></tr>
<tr><td align="center"><b>Seleccione la Empresa a representar:</b></td></tr>
<tr><td height="5"></td></tr>
<tr>
   <td align="center">
           <input type="hidden" name="idContribuyente" id="idcontribuyente">
               <input type="button" class="btn_empresa ui-button ui-widget ui-state-default ui-corner-all" style="width:100%" value="CASTRO SALVADOR" onclick="document.getElementById('idcontribuyente').value='0';document.seleccionaEmpresaForm.submit();" role="button">
   </td>
</tr>
<tr><td height="5"></td></tr>
</tbody></table>
</form>

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.action_chains import ActionChains
import time

# 配置Firefox的Selenium驱动
driver = webdriver.Firefox()

# 访问AFIP登录页面
driver.get("https://auth.afip.gov.ar/contribuyente_/login.xhtml?action=SYSTEM&system=admin_mono")
WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "F1:username"))).send_keys("xxxxxx")
WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "F1:btnSiguiente"))).click()
WebDriverWait(driver, 10).until(EC.visibility_of_element_located((By.ID, "F1:password"))).send_keys("xxxxx")
WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "F1:btnIngresar"))).click()

# 等待会话初始化完成
WebDriverWait(driver, 10).until(EC.url_contains("monotributo.afip.gob.ar"))

# 跳转到开票页面
driver.get("https://monotributo.afip.gob.ar/app/Facturacion.aspx")
WebDriverWait(driver, 10).until(EC.visibility_of_element_located((By.ID, "bBtn1")))

# 点击开票页面的初始按钮
WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "bBtn1"))).click()

# 等待元素可见（而非仅存在）
driver.implicitly_wait(2)
button = driver.find_element(By.XPATH, "//input[@value='CASTRO SALVADOR']")
driver.execute_script("arguments[0].click();", button)
button.click()

我还尝试了以下几种定位方式：

• 通过CSS选择器匹配类和value：

boton = driver.find_element(By.CSS_SELECTOR, "input.btn_empresa[value='CASTRO SALVADOR']")
boton.click()

• 通过CSS选择器匹配完整类名：

boton = driver.find_element(By.CSS_SELECTOR, "input.btn_empresa.ui-button.ui-widget.ui-state-default.ui-corner-all")
boton.click()

• 通过XPATH同时匹配类和value：

button = driver.find_element(By.XPATH, "//input[@class='btn_empresa' and @value='CASTRO SALVADOR']")
driver.execute_script("arguments[0].click();", button)

执行上述代码后，终端抛出如下错误：

Traceback (most recent call last):
  File "/Users/salvacastro/Desktop/afip.py", line 31, in <module>
    button = driver.find_element(By.XPATH, "//input[@class='btn_empresa' and @value='CASTRO SALVADOR']")
  File "/Users/salvacastro/Library/Python/3.9/lib/python/site-packages/selenium/webdriver/remote/webdriver.py", line 748, in find_element
    return self.execute(Command.FIND_ELEMENT, {"using": by, "value": value})["value"]
  File "/Users/salvacastro/Library/Python/3.9/lib/python/site-packages/selenium/webdriver/remote/webdriver.py", line 354, in execute
    self.error_handler.check_response(response)
  File "/Users/salvacastro/Library/Python/3.9/lib/python/site-packages/selenium/webdriver/remote/errorhandler.py", line 229, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.NoSuchElementException: Message: Unable to locate element: //input[@class='btn_empresa' and @value='CASTRO SALVADOR']; For documentation on this error, please visit: https://www.selenium.dev/documentation/webdriver/troubleshooting/errors#no-such-element-exception
Stacktrace:
RemoteError@chrome://remote/content/shared/RemoteError.sys.mjs:8:8
WebDriverError@chrome://remote/content/shared/webdriver/Errors.sys.mjs:193:5
NoSuchElementError@chrome://remote/content/shared/webdriver/Errors.sys.mjs:511:5
dom.find/<<@chrome://remote/content/shared/DOM.sys.mjs:136:16

针对NoSuchElementException问题，可从以下几个方向修复：

1. 优化等待策略 #

当前使用的driver.implicitly_wait(2)等待时间过短，且隐式等待与显式等待混用易出现冲突。建议统一使用显式等待，确保元素完全加载可点击：

# 替换原等待和定位代码
button = WebDriverWait(driver, 20).until(
    EC.element_to_be_clickable((By.XPATH, "//input[@value='CASTRO SALVADOR']"))
)
button.click()

2. 修正定位表达式 #

• XPATH匹配class时，因元素包含多个class，精确匹配@class='btn_empresa'会失败，改用contains匹配部分class：

button = WebDriverWait(driver, 20).until(
    EC.element_to_be_clickable((By.XPATH, "//input[contains(@class, 'btn_empresa') and @value='CASTRO SALVADOR']"))
)

• 或使用CSS选择器，无需匹配所有class，只需保留核心标识：

button = WebDriverWait(driver, 20).until(
    EC.element_to_be_clickable((By.CSS_SELECTOR, "input.btn_empresa[value='CASTRO SALVADOR']"))
)

3. 检查iframe场景 #

点击bBtn1后，目标元素可能处于iframe中，需先切换到iframe再定位：

# 按iframe的ID/索引切换，需替换为实际iframe标识
WebDriverWait(driver, 20).until(EC.frame_to_be_available_and_switch_to_it((By.ID, "目标iframe的ID")))
# 定位并点击按钮
button = WebDriverWait(driver, 20).until(
    EC.element_to_be_clickable((By.XPATH, "//input[@value='CASTRO SALVADOR']"))
)
button.click()
# 操作完成后切回主文档
driver.switch_to.default_content()

4. 直接模拟表单提交 #

既然按钮的点击逻辑是设置隐藏字段后提交表单，可跳过点击按钮，直接执行JS完成操作：

# 设置隐藏字段值
driver.execute_script("document.getElementById('idcontribuyente').value='0';")
# 提交表单
driver.execute_script("document.seleccionaEmpresaForm.submit();")

内容的提问来源于stack exchange，提问作者Salva Castro