Python Selenium StaleElementReferenceException

Question

我在其他帖子上看到过解决方案（主要是建议等待时间更长），但尝试过但没有成功。

这是我得到的错误：

Traceback (most recent call last):
  File "LobbyistsPrep.py", line 126, in <module>
    the_download = get_file(year, report, download_dir)
  File "LobbyistsPrep.py", line 28, in get_file
    Year.select_by_visible_text(year_text)
  File "C:\Python27\lib\site-packages\selenium\webdriver\support\select.py", lin
e 120, in select_by_visible_text
    self._setSelected(opt)
  File "C:\Python27\lib\site-packages\selenium\webdriver\support\select.py", lin
e 212, in _setSelected
    option.click()
  File "C:\Python27\lib\site-packages\selenium\webdriver\remote\webelement.py",
line 80, in click
    self._execute(Command.CLICK_ELEMENT)
  File "C:\Python27\lib\site-packages\selenium\webdriver\remote\webelement.py",
line 501, in _execute
    return self._parent.execute(command, params)
  File "C:\Python27\lib\site-packages\selenium\webdriver\remote\webdriver.py", l
ine 308, in execute
    self.error_handler.check_response(response)
  File "C:\Python27\lib\site-packages\selenium\webdriver\remote\errorhandler.py"
, line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.StaleElementReferenceException: Message: stale elemen
t reference: element is not attached to the page document
  (Session info: chrome=65.0.3325.181)
  (Driver info: chromedriver=2.33.506120 (e3e53437346286c0bc2d2dc9aa4915ba81d902
3f),platform=Windows NT 6.1.7601 SP1 x86_64)

以下是相关代码：

def get_file(year_text, category, download_dir):
    # Store a list of files in the Downloads directory.
    # We will use this later to determine the filename of the the CSV we downloaded.
    downloads_before = os.listdir( download_dir )

    # Change the Year dropdown
    Year = Select(driver.find_element_by_name('ctl00$ctl00$ContentPlaceHolder$ContentPlaceHolder1$ddYear'))
    Year.select_by_visible_text(year_text)
    time.sleep(30)

    # Change the Expenditure Type dropdown
    Type = Select(driver.find_element_by_name('ctl00$ctl00$ContentPlaceHolder$ContentPlaceHolder1$ddExpType'))
    Type.select_by_visible_text(category)
    time.sleep(30)

    # Change the Report Month dropdown
    Month = Select(driver.find_element_by_name('ctl00$ctl00$ContentPlaceHolder$ContentPlaceHolder1$ddMonth'))
    Month.select_by_visible_text('-- All Available --')
    time.sleep(30)

    # Click the Export to CSV button (downloads the CSV file)
    driver.find_element_by_name('ctl00$ctl00$ContentPlaceHolder$ContentPlaceHolder1$btnExport').click()
    time.sleep(30)

    # Now that we have downloaded the file, lets check the Downloads directory again and compare.
    downloads_after = os.listdir( download_dir )
    downloads_change = set(downloads_after) - set(downloads_before)
    # If there is only one difference, then that file is the one we downloaded.
    if len(downloads_change) == 1:
        file_name = downloads_change.pop()
        file_path = download_dir + file_name
        return file_path
    # Otherwise, something went wrong: Either the number of files changed by MORE than one, or NOTHING was downloaded.
    else:
        return False

driver.get('http://mec.mo.gov/mec/Lobbying/Lob_ExpCSV.aspx')
time.sleep(30)

for report in reports_wanted:
    for year in years_wanted:
        the_download = get_file(year, report, download_dir)
        if the_download:
            if report == 'Group':
                print 'Downloaded ' + the_download + '. Adding to GROUP.  Report:\t' + year + '\t' + report
                group_files.append(the_download)
            else:
                print 'Downloaded ' + the_download + '. Adding to INDIV.  Report:\t' + year + '\t' + report
                files.append(the_download)
        else:
            print 'PROBLEM DOWNLOADING: \t' + year + '\t' + report

我们的 time.sleep 曾经是 time.sleep(2) - 我尝试将其更改为 30，但这也无济于事。

我对调试爬虫还是很陌生，而且这个不是我建造的，所以请温柔一点。提前致谢。

Answer 1

我只有java中的解决方案，但它可以工作。

如果抛出异常，我会捕获它并重试：

boolean isElementFound = false;

while(!isElementFound){

  try{

     WebElement myElement = Driver.findElement(By.id("elementID"));
     isElementFound = true;   

  }catch(StaleElementReferenceException e){
    //nothing!
  } 
}

Answer 2

将解决问题的评论转化为其他人的答案。

最终解决上述问题的方法是将 Chromedriver 更新到至少 2.36，因为它们在 Chrome build 65 上运行，而当前版本的 Chromedriver 2.33 不支持： https://sites.google.com/a/chromium.org/chromedriver/downloads

通过保持这些是最新的，或者使用推荐的一对，您将遇到更少的问题，如 chromedriver 下载登陆页面所述。

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如果您正在寻求StaleElementReferenceException的帮助

这是来自 wiki 的定义：

当对元素的引用现在“过时”时抛出。

陈旧意味着元素不再出现在页面的 DOM 上。

StaleElementReferenceException 的可能原因包括但不包括 仅限于：

您不再在同一页面上，或者该页面可能有 自从找到元素后刷新。

该元素可能是 删除并重新添加到屏幕，因为它已被定位。比如一个 元素被重新定位。这通常会发生在 javascript 更新值并重建节点时的框架。

元素可能 已在 iframe 或其他已刷新的上下文中。

请参考这些：

• Selenium HQ page
• Wiki
• Answers from SO 在这个问题上的回答非常好

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