Selenium 和 Geckodriver 在 Python 中创建 Webdriver 时出现问题

我在 python 爬虫中有一段代码曾经可以工作。我将其安装在新系统上，现在正在尝试获取正确的依赖项。使用geckodriver 0.13.0并执行以下代码时：

        def login(self):
            print self.colors.OKBLUE + "Logging into my site as User: " + self.config.email + self.colors.ENDC
            username = self.driver.find_element_by_css_selector('.my_user_field')
            for c in self.config.email:
                    print "Sending key: " + c
                    username.send_keys(c + "")

我收到以下错误：

Sending key: b
Traceback (most recent call last):
  File "main.py", line 20, in <module>
    crawler.start()
  File "/home/tyrick/dev/pycrawlers/sc/src/main/python/new.py", line 39, in start
    self.login()
  File "/home/tyrick/dev/pycrawlers/sc/src/main/python/new.py", line 147, in login
username.send_keys(c)
   File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webelement.py", line 349, in send_keys
    'value': keys_to_typing(value)})
   File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webelement.py", line 493, in _execute
    return self._parent.execute(command, params)
   File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 256, in execute
    self.error_handler.check_response(response)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Expected [object Undefined] undefined to be a string

我在一些地方读到 geckodriver 有一个 bug，我应该使用 0.16.0。所以我尝试过 0.17.0，但现在收到以下错误：

Traceback (most recent call last):
  File "main.py", line 18, in <module>
    crawler = New()
  File "/home/tyrick/dev/pycrawlers/sc/src/main/python/new.py", line 28, in __init__
    self.driver = webdriver.Firefox()
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/firefox/webdriver.py", line 152, in __init__
keep_alive=True)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 98, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 188, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 256, in execute
    self.error_handler.check_response(response)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: elementScrollBehavior was not a the name of a known capability or a valid extension capability

好像我现在甚至无法初始化驱动程序。我正在使用 Selenium 3.4.3，据我所知，它很好。

如果有人可以指导我找到解决方案，我将非常感激！谢谢

你是对的，你有两个不同的问题。

问题与geckodriver 0.13.0:

这很可能是因为您的c is undefined.

您必须验证/断言self.config.email实际上返回一个有效的字符串（电子邮件）。所以检查一下c包含您在发出之前期望的电子邮件.send_keys()命令。

这里值得注意的另一个增强功能是在查找用户名字段时缺乏安全性。你应该使用显式等待 !

# Library imports
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

# (...)

def login(self):
    print self.colors.OKBLUE + "Logging into my site as User: " + 
    self.config.email + self.colors.ENDC

    # Polls the DOM for 3 seconds trying to find '.my_user_field'
    username = WebDriverWait(self.driver, 3).until(EC.presence_of_element_located((By.CSS_SELECTOR, '.my_user_field')))

    for c in self.config.email:

        # Validate 'c' is of type string
        if (str(type(c)).find('str') != -1):  
            print "Sending key: " + c
            username.send_keys(c + "")
        else:
            print "'c' is not what it used to be!"

最后，添加完整的代码片段，因为看起来您正在循环浏览电子邮件列表并在之前找到的用户名字段中发送它们。

问题与geckodriver 0.16.0:

这是失败的，因为您的驱动程序实例化存在问题：self.driver = webdriver.Firefox().

请使用驱动程序声明的完整片段（包括功能和配置文件，如果有）更新问题。否则，很难找出错误的原因。