在 Selenium 中将 PhantomJS 用于无头浏览器 - Python答案

【问题标题】：Using PhantomJS for headless browser in Selenium - Python在 Selenium 中将 PhantomJS 用于无头浏览器 - Python
【发布时间】：2016-01-30 00:23:59
【问题描述】：

我目前正在使用Python-Selenium 运行一些测试。它应该是登录网页，输入username和password，然后做一些其他的事情。当我使用Firefox 浏览器执行它时，它工作正常，但是当我使用PhantonJS 时，我收到以下错误：

2016-01-29 16:18:29 - ERROR - An exception occurred Message: {"errorMessage":"Unable to find element with id 'user_email'","request":{"headers":{"Accept":"application/json","Accept-Encoding":"identity","Connection":"close","Content-Length":"91","Content-Type":"application/json;charset=UTF-8","Host":"127.0.0.1:57257","User-Agent":"Python-urllib/2.7"},"httpVersion":"1.1","method":"POST","post":"{\"using\": \"id\", \"sessionId\": \"fcd54080-c6e6-11e5-94bd-27954be890c7\", \"value\": \"user_email\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/fcd54080-c6e6-11e5-94bd-27954be890c7/element"}}
Screenshot: available via screen
Traceback (most recent call last):
  File "webcrawler.py", line 105, in login
    email = self.singleton.driver.find_element_by_id("user_email")
  File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 234, in find_element_by_id
    return self.find_element(by=By.ID, value=id_)
  File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 712, in find_element
    {'using': by, 'value': value})['value']
  File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 201, in execute
    self.error_handler.check_response(response)
  File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/errorhandler.py", line 181, in check_response
    raise exception_class(message, screen, stacktrace)
NoSuchElementException: Message: {"errorMessage":"Unable to find element with id 'user_email'","request":{"headers":{"Accept":"application/json","Accept-Encoding":"identity","Connection":"close","Content-Length":"91","Content-Type":"application/json;charset=UTF-8","Host":"127.0.0.1:57257","User-Agent":"Python-urllib/2.7"},"httpVersion":"1.1","method":"POST","post":"{\"using\": \"id\", \"sessionId\": \"fcd54080-c6e6-11e5-94bd-27954be890c7\", \"value\": \"user_email\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/fcd54080-c6e6-11e5-94bd-27954be890c7/element"}}
Screenshot: available via screen

再调试问题，发现页面内容是：

DEBUG - <html><head></head><body></body></html>

这是我开始Selenium driver：

def __init__(self, browser="phantomjs"):
        if browser == "phantomjs":
            self.driver = webdriver.PhantomJS()
            self.driver.set_window_size(1120, 550)
        elif browser == "firefox":
            self.driver = webdriver.Firefox()
        elif browser == "chrome":
            self.driver = webdriver.Chrome()
        elif browser == "remote":
            self.driver = webdriver.Remote()
        elif browser == "ie":
            self.driver = webdriver.Ie()
        else:
            raise ValueError("Invalid browser value:  %s"  % browser)

谁能告诉我如何解决这个问题？它使用 Firefox 可以完美运行，但我将把它部署在 AWS 的一个节点中，所以我需要使用一些无头浏览器。

【问题讨论】：

标签： python selenium phantomjs

【解决方案1】：

@alecxe 给出的选项也是有效的。在我的特殊情况下，网页使用SSL，因此解决方案是将PhantomJS 创建为：

self.driver = webdriver.PhantomJS(service_args=['--ignore-ssl-errors=true', '--ssl-protocol=any'])

还要确保设置窗口大小，以创建虚拟浏览器：

self.driver.set_window_size(1120, 550)

【讨论】：

是的，我记得使用 --ignore-ssl-errors 标志也可以解决不同的 PhantomJS 特定问题。谢谢。

【解决方案2】：

首先，你仍然可以在 AWS 上使用Firefox，只需在虚拟显示器下运行即可：

How do I run Selenium in Xvfb?

至于您的 PhantomJS 特定问题，您需要一个 wait - 等待该元素的存在：

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

wait = WebdriverWait(driver, 10)

email_element = wait.until(EC.presence_of_element_located((By.ID, "user_email")))
email_element.send_keys(email)

【讨论】：