selenium.common.exceptions.UnexpectedAlertPresentException: Alert Text: Message: unexpected alert open:

Traceback (most recent call last):
  File "D:/selenium/ZenTaoTestPro/Action/login_action.py", line 40, in <module>
    login.login_fail('test', 'test001')
  File "D:/selenium/ZenTaoTestPro/Action/login_action.py", line 27, in login_fail
    self.login_action(username, password)
  File "D:/selenium/ZenTaoTestPro/Action/login_action.py", line 17, in login_action
    self.login_page.screenshot_as_file()
  File "D:\selenium\ZenTaoTestPro\common\base_page.py", line 284, in screenshot_as_file
    self.driver.get_screenshot_as_file(screenshot_filepath)
  File "D:\Software\python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 1032, in get_screenshot_as_file
    png = self.get_screenshot_as_png()
  File "D:\Software\python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 1064, in get_screenshot_as_png
    return base64.b64decode(self.get_screenshot_as_base64().encode('ascii'))
  File "D:\Software\python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 1074, in get_screenshot_as_base64
    return self.execute(Command.SCREENSHOT)['value']
  File "D:\Software\python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 321, in execute
    self.error_handler.check_response(response)
  File "D:\Software\python\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 241, in check_response
    raise exception_class(message, screen, stacktrace, alert_text)
selenium.common.exceptions.UnexpectedAlertPresentException: Alert Text: 
Message: unexpected alert open: <unknown>
  (Session info: chrome=81.0.4044.138)


Process finished with exit code 1

定位上述错误地方：

  File "D:/selenium/ZenTaoTestPro/Action/login_action.py", line 17, in login_action
    self.login_page.screenshot_as_file()
  File "D:\selenium\ZenTaoTestPro\common\base_page.py", line 284, in screenshot_as_file
    self.driver.get_screenshot_as_file(screenshot_filepath)
  File "D:\Software\python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 1032, in get_screenshot_as_file
    png = self.get_screenshot_as_png()

　　是因为调用方法里写的 self.driver.get_screenshot_as_file(screenshot_filepath) 导致的错误；将方法中的这块删除就能解决问题：

# 错误代码
def login_action(self, username, password):
        self.login_page.implicitly_wait()
        self.login_page.input_username(username)
        self.login_page.input_password(password)
        self.login_page.click_login_button()
        # self.login_page.screenshot_as_file()   #删除

# 调用    
def login_fail(self, username, password):
        self.login_action(username, password)
        return self.login_page.get_login_fail_alert_content()

# 调试
if __name__ == '__main__':
    driver = Browser().get_driver()
    login = LoginAction(driver)
    bp = BasePage(driver)
    bp.open_url(local_config.test_url)
    login.login_fail('test', 'test001')

　　这样就解决问题了。